Laser Diode Structure and Precautions for Use
As we all know, laser technology has penetrated into all fields of national economy and national defense construction. The huge market for compact disks (CDs) drives the technological development of semiconductor lasers, and the birth of red light semiconductor laser diodes pushes laser technology to a new stage of development. At present, there are numerous manufacturers in the world have developed and produced laser diodes. Laser diode products by wavelength and power classification has formed a series, and continue to short-wave and high-power development.Small red semiconductor lasers (light sources) composed of laser diodes with optics and cooling systems are being used in a large number of industries such as line throwers, scanning guns, medical treatment, and aiming instructions.
The following is an example of a QSI red laser diode QL65D5SA-P, with a brief description of its structure and precautions for use.
Structure and working process
(1) Structure
Semiconductor laser diode QL65D5SA-P working wavelength of 650mm, belongs to the category of visible light, so it is also known as red semiconductor laser diode. Its shape is shown in Figure 1 (a), the internal structure is shown in Figure 1 (b), the electrical symbols shown in Figure 1 (c). The cathode electrode of VD1, which emits laser light, is connected to pin ①, and the anode and tube shell are connected to pin ②. In addition, there is a photodiode VD2 that receives the laser light from VD1, and its cathode and anode are connected to pins ② and ③, respectively.
Precautions for use
① Anti-static: when taking the tube or welding pins, the hand must bring a grounding wrist strap (wrist strap series 1MΩ resistor grounding, as shown in Figure 3, to prevent the human body from carrying static electricity damage to the tube.
② welding: welding, soldering iron shell should be grounded, it is best to unplug the power plug from the socket. Welding time should be short (maximum welding temperature of 260 ℃, welding time is less than 5s), a weld is not secure after a certain period of time can be welded again.
③ Working current: Do not adjust it to exceed the maximum value, and do not overshoot the current. Prevent disconnection in the adjustment, otherwise it will burn the tube. AC and DC work can be, but the peak value should not exceed the maximum value.
④ If you do not need to monitor the output, you may not use VD2.
⑤ Prevent the laser beam from hurting your eyes: When the laser is working, you should not look at the light source directly or through reflection, otherwise it will hurt your eyes. According to international practice, a warning label should be attached to the laser.