Connect the two-frequency laser diode AN 40. The driver for the laser diode is the laser connection diagram. About laser diode
Laser diodes - Previously, the manufacture of lasers was associated with great difficulties, since this requires a small crystal and the development of a scheme for its operation. For a simple radio amateur, such a task was impracticable.
With the development of new technologies, the possibility of obtaining a laser beam in domestic conditions has become a reality. The electronic industry today produces miniature semiconductors that can generate a laser beam. Laser diodes became these semiconductors.
Increased optical power and excellent functional parameters of the semiconductor allow it to be used in measuring devices of increased accuracy both in production, in medicine and in everyday life. They are the basis for recording and reading computer discs, school laser pointers, level gauges, distance meters and many other devices beneficial to humans.
The emergence of such a new electronic component is a revolution in the creation electronic devices Different complexity. Diodes high power Form a beam, which is used in medicine when performing various surgical operations, in particular to restore vision. The laser beam is able to quickly adjust the eye lens.
Laser diodes are used in measuring instruments in everyday life and industry. Devices are made with different power. The power of 8 W is enough for the assembly in domestic conditions of a portable level gauge. This device is reliable in operation, it is capable of creating a laser beam of a very long length. The entry of the laser beam in the eyes is very dangerous, since at a small distance the beam is capable of damage to the soft tissues.
Device and principle of operation
In a simple diode on the anode, a positive voltage is supplied, then we are talking On the displacement of the diode in the forward direction. The holes from the region "P" are injected into the area "N" of the r - n of the transition, and from the region "n" to the region of the semiconductor. When the hole is located and the electron next to each other, they are recombined and release photon energy with some wavelength and phonon. This process was called spontaneous radiation. In LEDs, it is the main source.
But under certain conditions, the hole and the electron are able to be in front of recombination in one place for a long time (several microseconds). If in this area at this time a photon will be held with a frequency of resonance, he will cause forced recombination, and the second photon will be selected. His direction, phase and polarization vector will absolutely coincide with the first photon.
The semiconductor crystal is made in the form of a thin plate form of a rectangle. In essence, this plate also plays the role of an optical waveguide, in which radiation acts in a limited amount. The surface layer of the crystal is modified in order to form the domain "N". The lower layer is used to create the area "P".
Ultimately, a flat transition of the Pl is a significant area. Two crystal side end is polished to create parallel smooth planes forming an optical resonator. A random photon perpendicular to spontaneous radiation planes will be held throughout the optical wave. At the same time, before going out, the photon will be reflected several times from the ends and, passing along the resonators, will create forced recombination, while forming new photons with the same parameters as the radiation increases. When the gain surpasses losses, the creation of a laser beam will begin.
There are various types of laser diodes. The main of them are made on particularly thin layers. Their structure is capable of creating radiation only in parallel. But if the waveguide is widespread in comparison with the wavelength, it will already function already in various transverse modes. Such laser diodes are called multi-way.
The use of such lasers is justified to create an increased radiation power without high-quality beam convergence. It is allowed some dispersion. This effect is used to pump other lasers, in chemical production, laser printers. However, if necessary, a certain focusing of the beam, the waveguide must be performed with a width comparable to a wavelength.
In this case, the width of the beam depends on the boundaries that are applied with diffraction. Such devices are used in storage optical devices, fiber optic technique, laser signs. It should be noted that these lasers are not able to maintain several longitudinal modes, and emit a laser beam on different wavelengths at one time. The prohibited zone between the energy levels "p" and "n" of the diode regions affects the wavelength of the beam.
The laser beam at the outlet immediately dispel, as the emitting component is very thin. To compensate for this phenomenon and create a thin ray, collect lenses use. Cylindrical lenses are used for wide multi-dimensional lasers. In the case of single-bar lasers, when using symmetric lenses, the laser beam will have an elliptical cross-section, since the vertically discrepancy exceeds the size of the beam in the horizontal plane. A visual example is a laser pointer for this.
In the considered elementary device, a certain wavelength cannot be distinguished, except for the wave of an optical resonator. In devices having a material capable of enhancing the beam in a large frequency range, and with several modes, it is possible to effect on different waves.
Typically, laser diodes are functioning on a single wave, which has a significant instability, and depending on various factors.
Varieties
The device discussed above the diodes has n-p structure. Such diodes have low efficiency, require significant power at the input, and operate only in pulse mode. In a different way, they can not work, as they will quickly overheat, therefore they have not received widespread use in practice.
Double heterostructure lasers have a layer of substance with a narrow forbidden zone. This layer is between the layers of the material that has a widely prohibited zone. Usually for the manufacture of a laser with a double heterostructure, an arsenide of aluminum-gallium and gallium arsenide are used. Each of these compounds with two different semiconductors were called heterostructure.
The advantage of lasers with such a special structure is that the area of \u200b\u200bholes and electrons, which is called the active region, is on average thin layer. Therefore, it is much greater than the pairs of holes and electrons will create a strengthening. In the area with a small strengthening of such steam, there will be little. In addition, the light will be reflected from the heteroofers. In other words, radiation will be fully in the area of \u200b\u200bthe greatest efficient gain.
Diode with quantum pits
When performing the middle layer of the diode is thinner, it begins to function as a quantum pit. Therefore, electronic energy will be quantized vertically. The difference between the energy levels of quantum holes is used to form radiation instead of the future barrier.
This is effective for controlling the beam wave, depending on the thickness of the middle layer. This type of laser is much more efficient, unlike the single-layer, since the density of holes and electrons is distributed more evenly.
Heterostructural laser diodes
The main feature of thin-layer lasers is that they are not able to effectively hold the ray of light. To solve this problem on both sides of the crystal, two additional layers are applied, which have a lower refraction, in contrast to the central layers. A similar structure is similar to the light guide. It is much better holding the beam. This is a heterostructure with a separate retention. This technology produced most lasers in the 90s.
Feedback Lasers basically used for fiber optic communication. To stabilize the wave on p-N transition Perform a transverse notch to create a diffraction lattice. Because of this, only one wavelength is returned to the resonator. Such lasers have a permanent wavelength. It is determined by the step of lattice notches. Under the action of temperature, notch changes. Such a laser model is the basis of telecommunication optical systems.
There are also laser diodes VSSSEL and VESSEL which are superficially emitting models with a vertical resonator. Their difference is that the model has VESSEL The external resonator, and its design happens with optical and current pumping.
Connection features
Laser diodes are used in many devices where directional beam is needed. The main process in the assembly of the device with the use of the laser is your own hands is the correct connection.
Laser diodes differ from LED diodes with a miniature crystal. Therefore, it concentrates high powerAnd therefore the current value that can lead to its failure. To facilitate the laser, there are special schemes of devices that are called drivers.
Lasers need stable food. However, there are their models having a red beam glow, and functioning in normal mode even with an unstable network. If there is a driver, then all the same diode cannot be connected directly. For this, the current sensor needs additionally, the role of which often plays a resistor connected between these elements.
Such a connection has a disadvantage that the negative power supply is not connected to the minus scheme. Another disadvantage is the drop in power on the resistor. Therefore, before connecting the laser, you must carefully pick up the driver.
Types of drivers
There are two main types of drivers capable of ensuring the normal mode of operation of laser diodes.
Pulse driver Made by analogy pulse converter Voltages capable of raising and lowering this parameter. The output and login power of such a driver is approximately equal. However, there is some heat release, which is consumed by a slight amount of energy.
Linear driver Specifies according to the scheme, which most often serves a voltage on a diode greater than required. To reduce it, a transistor is needed that converts excessive energy into heat. The driver has a small efficiency, so he did not find widespread use.
When using linear microcircuits as stabilizers, with a decrease in voltage at the inlet, the diode current will decrease.
Since lasers are powered by two types of drivers, the connection schemes have differences.
The scheme may also contain a power source as a battery or battery.
Batteries must produce 9 volts voltage. Also in the diagram there must be a resistor, limiting current, and a laser module. Laser diodes can be found in a faulty drive drive from a computer.
Laser diode has 3 outputs. The average output is connected to a minus (plus) of nutrition. Plus connects to the right or left leg, depending on the manufacturer's company. To determine the desired foot for connecting, you must apply power. To do this, you can take two batteries of 1.5 V and resistance of 5 ohms. The minus of the source is connected to the middle leg of the diode, and plus first to the left, then to the right leg. By such an experiment, you can see which of these legs is a "worker". In the same method, the diode is connected to the microcontroller.
Laser diodes can work from finger batteries, batteries cell phone. However, it is impossible to forget that further requires a limiting resistor with a face value of 20 ohms.
Connect to household network
To do this, you need to provide auxiliary protection against high-frequency voltage bursts.
The stabilizer and resistor create a block preventing current drops. Stabilirton is used to equalize the voltage. The container prevents the occurrence of high frequency voltage jumps. With proper assembly, a stable operation of the laser is ensured.
Connection order
The most convenient for work will be a red diode with a capacity of about 200 MW. Such laser diodes are installed on disk drives of computers.
- Before connecting with a battery, check the operation of the laser diode.
- Select the most bright semiconductor. If the diode is taken from disk drive Computer, then it shines in infrared light. The laser beam is prohibited from damage to the eye, as it will damage the eye.
- Diode Mount to the radiator for cooling, as an aluminum plate. To do this, pre-drill the hole.
- Between the diode and the radiator, the thermal stroke.
- 20 Ohm resistor and 5 watts connect according to a diagram with batteries and a laser.
- Diode shunt a ceramic capacitor of any capacity.
- Unscrew from yourself a diode and check it out, connecting the power. A red beam should appear.
When connected, you should remember the safety. All connections must be high quality.
When generating laser radiation, a laser diode current is more important, but its voltage. At the time of filing a positive potential on the anode, the offset begins p-N Transition in direct direction. It begins the injection of holes from the p-zone in N and similar injecting electrons in the opposite direction. The close arrangement of electrons and holes launches their recombinations. This action accompanied by generation of photons of a certain wavelength
This physical phenomenon obtained the name of spontaneous radiation and in relation to laser diodes is considered the main method of generating laser radiation. 
The semiconductor crystal of the laser diode is a thin rectangular plate. The division on the P and N of the part here is carried out according to the principle not to the right side, but from top to bottom. That is, the P-region is located in the upper part of the crystal, and below the N-region.
therefore p-N The transition is large enough. The laser diode the end sides are polished, because for the formation of an optical resonator (Fabry-Pen), it is necessary for the presence of parallel planes of maximum smoothness. Perpendicularly directed towards one of them photon will move throughout the optical waveguide, periodically reflecting from the side end sides until it comes out of the resonator.
During such a movement, the photon provokes several acts of forced recombination, i.e. generating similar photons and thereby enhancing laser radiation. At that time when the amplification is enough to overlap the loss, laser generation begins.
The main distinctive feature between LEDs and laser diodes is the width of the emission spectrum. LEDs have a wide range of radiation, while lasers have a very narrow spectrum.
The principle of operation of both semiconductor sources is based on the phenomenon of electroluminescence-radiation of light by material through which flows electricitycaused by an electric field. The radiation due to the electroluminescence is characterized by a relatively narrow spectrum of a width of 0.1 ... 3 nm for laser diodes and 10 ... 50 nm at LEDs.
To connect a laser diode special electronic circuit, called the laser diode driver. In the practical example, we will show you how to collect a simple laser diode driver based on the voltage stabilizer LM317.
The driver is a special connection diagram that is used to limit the current and further feed it to the laser diode so that it works correctly and has burned down when the first is turned on, if we directly connect it to the power supply.
If the current is a low laser LED will not be turned on due to the lack of the required power level. Thus, the driver diagram is intended to provide a correct current nominal, in which the laser diode will go into its working condition. Simple LED Enough the usual resistor to limit the current, but in the case of the laser, we will need a connection scheme to limit and adjust the current. For these purposes, microsite care is perfect.
Three-line chip LM317 is a typical voltage stabilizer. At its output, it can produce a voltage from 1.25 to 37 volts. Appearance LM317 with signed conclusions is presented in the image above.
The microcircuit is an excellent adjustable stabilizer, in other words, you can easily change the voltage value on the output depending on the needs of the circuit output using two external resistance connected to the adjustment line (Adjust). These two resistors work as a voltage divider used to reduce output voltage.
The design in five minutes can be collected on male Plate. The scheme works like this. When the battery starts to go with a voltage of 9 volts, it first flows through a ceramic condenser (0.1 μF). This container is used to filter high-frequency noise from the source. direct current and provides the input signal for the stabilizer. The potentiometer (10 com) and resistance (330 ohms) connected to the setup lines are used as a voltage limit scheme. The output voltage depends entirely on the value of these resistance. The output voltage of the stabilizer falls on the second capacitor filter. This container behaves as a power balancing when filtering fluctuating signals. As a result, the intensity of laser radiation can be changed, rotating the potentiometer knob.
This scheme, fairly accurate and not requiring a large number of components, is designed to control the laser diode and is designed in accordance with the requirements for medical equipment. Now the device passes clinical trials. The characteristics of laser diodes are subject to short and long-term drift due to temperature and aging. Usually they are controlled by a constant current, therefore their output optical power is monitored and, in accordance with its changes, regulate the current.
The construction body is grounded, so the configuration of the DC source is designed to include the power transistor into the top of the laser shoulder, and not the easiest option of the opposite option. In addition, to avoid the "tattoo" of the patient, the current must be initially limited.
In a scheme with a unipolar diet +5 to a resistor R1, measuring and limiting current, and the P-channel MOS-transistor Q1 form a source repeater (Figure 1). The MOS-transistor's shutter is under voltage, slightly exceeding the source voltage, so the transistor is partially open, and the laser diode current creates a voltage drop on the R1 resistor. In the worst case, when Q1 is open completely, the maximum laser current is determined by the expression
R DS (SAT) \u003d 25 MΩ - Resistance open Canal MOS-transistor,
V Laser \u003d 2.0 V - voltage on the laser diode.
R DS (SAT) and V Laser values \u200b\u200bwere taken from reference data on a transistor and a laser diode, respectively. The resistance of the resistor R1 is determined by the requirements for the magnitude of the laser current (in this case, 250 mA), taking into account the correction made by the direct voltage of the laser diode, the typical value of which is 2.0 V. solving equation relative to R1, we get:
where I Laser \u003d 250 mA.
Resistance R DS (SAT) is so small that it can be not taken into account. With known values \u200b\u200bof R1 and the maximum current of the laser diode, the power dissipated by R1 can be calculated by the formula
from where it follows that a resistor with a permissible 500 MW capacity will provide a small additional supply.
The magnitude of the laser current is set using the DAC, the output voltage of which is set to logometrically. The source voltage is used as a reference here +5 B, so the DAC output tracks all power fluctuations. During operation at the ADC output, the required value of the control voltage is set. The divider R2, R3 scales this setpoint relative to the nominal power supply +5 V.
For example, if the Output voltage of the DAC is set to half the scale, that is, +2.5 V, the voltage between R2 and R3, (or on the non-converting input of the IC1 OU), will be +3.5 V. Included in the feedback circuit IC1 adjusts the voltage on the q1 gateway and , respectively, the current passes through R1, Q1 and laser diode. The scheme mode is stabilized when the feedback voltage becomes equal to +3.5 V. In this steady mode on the resistor R1, 5 V - 3.5 V \u003d 1.5 V, and the current is 125 mA, that is, is in the middle of the scale. Similarly, if at the output of the DAC set the minimum value of 0 V, the voltage on the non-converting input IC1 will be +2 V. IC1 will increase the voltage on the valve Q1 until the voltage drop to R1 will grow to 3 V, and the current, respectively, up to 250 mA. This is the saturation point in which Q1 is completely open, and the direct voltage on the laser diode is +5 in minus the voltage drop on R1.
IN full scheme Elements R4 and C1 must be included, ensuring the stability of the control circuit and having a cut frequency F equal to
Special attention should be paid to the process occurring in the diagram with a hopping change of control voltage, for which OU, who worked before this, as an adder of voltages of setpoint and feedback, becomes the voltage repeater, and the step is striving at its output. In this regard, in our example, a capacitor C2 is added, forming a low-frequency filter voltage filter with a slice frequency
where R2 || R3 \u003d 12 com.
If the cutoff frequency of this filter is much less than the OS circuit bandwidth, the OS will be able to track stepped setpoint changes with minimal emissions during the switching of the DAC.
R5 provides some OS offset due to the fact that a small current will always be guaranteed to flow through the R1 resistor. When the DSC output is set to the full scale voltage +5 V, the laser current defined by the operating amplifier will always slightly exceed the value defined by the setting. Therefore, the OU output, trying to turn off Q1, will be in saturation. Without a resistor R5, the input voltage of the OU offset could be perceived as a false setpoint value and led to switching on Q1 to restore balance.
This is one of the main reasons for which the logometric inclusion of the DAC is used. If the support voltage of the DAC was fixed, the programming of small currents would be almost impossible. If at the output of the DAC set the voltage is slightly lower than the exact value of +5 V, even with small supply voltage fluctuations +5 to the control voltage will be changed very significantly. However, in the Logometric diagram, the DAC monitors the supply voltage changes +5 V, and the relative control voltage at its outlet remains stable.
A pay for the ability to accurately set weak currents is a bad power pulsation coefficient. However, medical applicationFor which the laser was intended, the current stabilization loop itself is part of the power stabilization loop, and the nutritional pulsation in it is minimal. If you need, you can add a small voltage stabilizer on the fee, and the price of some increase in the number of components you will receive a stable, low-noise laser power.
The dream of a small pocket laser has become a reality with the emergence and development of semiconductor laser diodes. In the Internet, there are quite a lot of articles about how you can make a burning laser from the drive for a CD. But you should not be limited to only this information.
Select a laser diode:
If you wondered to make a laser, then review the directory and select the laser diode suitable by parameters. If you do not have a faulty DVD RW drive - then you will have to get up and buy a laser LED. And in this case, you can moderate your financial capabilities, choose the laser you need power. And how to be next with him? I recommend reading and listening to our article to not waste time on the assembly of dubious schemes for connecting the laser diode.
Laser installation classification:
High energy concentrates in the laser beam and therefore there is a danger to damage the vision in careless handling of lasers. There is a classification of the danger of laser installations in accordance with EN60825-1 Figure No. 1.
Figure No. 1 - Classification of the danger of laser installations When working with laser diodes, it is necessary to strictly follow the safety regulations. You can not direct the laser beam directly in the eye, it can lead to full or partial loss of vision. Do not give your laser installation to children, do not leave it in easily accessible places! Exclude the possibility of non-authorized (random) laser inclusion, use your creation only for peaceful purposes !!! Dress up safety glasses when setting up and working with it.
About laser diode:
As a rule, a laser diode is a miniature device with three (Figure No. 2) or four legs depending on the type.
Figure No. 2 - Exterior Laser LED with three legs Why three legs? The fact is that inside the housing is located in addition to the laser emitting diode, the photodiode Figure No. 3 is also.
Figure No. 3 - Laser LED Scheme Photodiode is designed to control the laser current (adjust or limit). Structurally, it looks like this: Figure No. 4.
Figure No. 4 - laser diode rotation. Low-power laser diodes are operated with slightly volts and current power in the range of about 50 to 80 mA. Specified in the corresponding passports on them (Datasheet). For example, the operating current (50-60 mA) cannot be exceeded! Pulsed overloads are also dangerous. Therefore, when the laser LED is nutrition, it is necessary to take into account that such peaks are absent. It is more interesting to use as a power supply for diode a power supply, but batteries. But it is not always suitable - especially if you want to make a stationary installation.
So, if you wish to connect your laser diode (LD) to a non-stabilized (simple) power supply, we recommend using a diagram of Figure No. 5:
Figure No. 5 - LD connection scheme to an unstabilized power source C1-10 ICF.
C2 - 47 PF
C3, C4 - 10 NF
R1 - 10 to
R2 - 1.5 to
R3 - 33 Ohm
VT1 - Sun548.
VT2 -BD675
VD1 - Laser Diode
VD2 - 3.3 V / 1.3W
Thanks to this connection, the laser diode can be prevented by way out. The voltage drop on the R2 resistor opens the VT 1 transistor, it controls the transistor current of the VT 2. In the control circuit of the photodium current ranges about 400 μs. Capacitor C4 eliminates pulse interference, and a capacitive voltage divider consisting of C2 and SZ capacitors ensures that the control process is immediately launched when the supply voltage is applied.
My laser version:
I also tried to make a laser from a DVD RW drive and I want to warn you right away that the idea is good, but it is quite difficult to realize it. Disassemble the working DVD RW drive is stupid, and in broken drives, as a rule, a laser diode is not subject to restoration. Even if you still managed to remove the working laser diode, then be prepared for the fact that a special collecting lens is needed to it, since the laser diode itself shines not focused. And what would form the required discrepancy between the beam you need good optics. Lenses from DVD RW Drive Do not give the desired effect. I simply bought a ready-made laser module of type HLDPM12-655-5 (in the housing with optics and protection against cords), and connected it to the ordinary power supply.
Make a powerful burning laser with your own hands - an easy task, however, besides the ability to use the soldering iron, the attentiveness and accuracy of the approach will be required. Immediately it is worth noting that deep knowledge from the field of electrical equipment is not needed here, and it is possible to make the device even at home. The main thing when working is observance of precautions, as the effect of the laser beam is detrimental to the eyes and skin.
Laser is a dangerous toy that can harm health when it is inaccier. Do not send a laser for people and animals!
What will required?
Any laser can be divided into several components:
- emitter of the light flux;
- optics;
- power supply;
- current power stabilizer (driver).
To make a powerful homemade laser, it will be necessary to consider all these components separately. The most practical and easy to assemble is the laser diode laser, and consider it in this article.
Where to take a diode for a laser?
The working body of any laser is a laser diode. It can be bought in almost any store radio engineering, or get out of the non-working drive for CDs. The fact is that the inoperability of the drive is rarely connected with the failure of the laser diode. Having in the presence of a broken drive, you can use the desired item without unnecessary costs. But it is necessary to consider that its type and properties depend on the modification of the drive.
The weakest infrared laser is installed in CD-ROM drives. Its power is enough only to read CD discs, and the beam is almost invisible and it is not able to burn objects. The CD-RW includes a more powerful laser diode suitable for the burning and calculated on the same wavelength. It is considered the most dangerous, as the ray of the ray of the spectrum is invisible to the eye.
DVD-ROM drive is equipped with two weak laser diodes, the energy of which is enough only to read CD and DVDs. A red laser is installed in the Writing Drive DVD-RW big power. Its beam is visible at any lighting and can easily ignite some objects.
The BD-ROM is a purple or blue laser, which is similar to the parameters with analogue from the DVD-ROMA. From the BD-RE writing, you can get the most powerful laser diode with a beautiful purple or blue beam capable of burning. However, it is difficult to find such a drive to disassemble enough, and the working device is expensive.
The most suitable is the laser diode taken from the writing drive of DVD-RW disks. The highest quality laser diodes are installed in LG, Sony and Samsung drives.
The higher the speed dVD records Drive, the more powerful laser diode is installed in it.
Hearing drive
Having a drive, the first thing is removed the top cover, unscrewing 4 screws. Then remove the movable mechanism that is in the center and is connected to pCB flexible loop. The following goal is a laser diode, reliably pressed in a radiator from an aluminum or duralumin alloy. It is recommended to protect against static electricity before it dismark. For this, the conclusions of the laser diode solder or wrapped with a thin copper wire.
Further two options are possible. The first implies the operation of the finished laser in the form of a stationary installation together with a regular radiator. The second option is an assembly of a device in a portable lantern case or laser pointer. In this case, it will have to make force to launch or cut the radiator without damaging the emitting item.
Driver
The laser nutrition must be considered responsibly. As for LEDs, it should be a source of stabilized current. On the Internet there are many schemes with a battery or battery through a restrictive resistor. The sufficiency of such a solution is doubtful, since the voltage on the battery or batteries changes depending on the level of charge. Accordingly, the current flowing through the radiating diode of the laser will be very deviated from the nominal value. As a result, at small currents, the device will not work effectively, and in large - will lead to a rapid decrease in the intensity of its radiation.
The optimal option is considered to use the simplest current stabilizer built on the basis. This microcircuit refers to the category of universal integral stabilizers with the possibility of self-task and voltage at the output. The chip is operating in a wide range of input voltages: from 3 to 40 volts.
Analogue LM317 is the domestic chip KR142EN12.
For the first laboratory experiment, the scheme is suitable below. The calculation of the only resistor in the diagram is made according to the formula: R \u003d I / 1.25, where i is the rated laser current (reference value).
Sometimes at the output of the stabilizer parallel to the diode, the polar capacitor is installed at 2200 μF16 V and a non-polar capacitor by 0.1 μF. Their participation is justified in the case of supplying voltage to the entrance from the stationary power supply, which can miss a minor variable component and pulse interference. One such schemes designed to feed from the Krone battery or a small battery is presented below. 
The diagram indicates the approximate value of the resistor R1. To accurately calculate, it is necessary to use the above formula.
Colmia electrical circuit, It is possible to pre-enable and as proof of the performance of the scheme, observe the bright red scattered light of the radiating diode. Having measured its real current and body temperature, it is worth thinking about the need to install the radiator. If the laser is used in the stationary installation on high currents for a long time, then it is necessary to provide passive cooling. Now it remains quite a bit to achieve the goal: make focusing and get a narrow right beam of high power.
Optics
I am expressed by scientifically, it's time to build a simple collimator, a device for obtaining parallel light rays. An ideal option for this purpose will be a regular lens taken from the drive. With it, you can get a rather thin laser beam with a diameter of about 1 mm. The amount of energy of such a beam is enough to break through the paper, fabric and cardboard in counting seconds, melted plastic and burn on wood. If you focus a thinner ray, you can cut the phaneer and plexiglass. But set up and securely secure the lens from the drive is quite difficult due to its small focal length.
It is much easier to build a collimator based on laser pointer. In addition, in its package, you can put a driver and a small battery. At the output, the beam in diameter is about 1.5 mm of smaller burning action. In foggy weather or with abundant snowfall, you can observe incredible lighting effects, sending the light stream into the sky.
Through an online store, you can purchase a ready-made collimator, specially designed for fastening and setting up a laser. His body will serve as a radiator. Knowing the size of all components of the device, you can buy a cheap LED flashlight and take advantage of it.
In conclusion, I would like to add several phrases about the danger of laser radiation. First, never direct the laser beam in the eyes of people and animals. This leads to serious violations of vision. Secondly, during experiments with a red laser, wear green glasses. They prevent the passage of most of the red component of the spectrum. The amount of light that passed through the glasses depends on the length of the radiation wave. View from the side of a laser beam without protective means is allowed only briefly. Otherwise, pain in the eyes may appear.
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