Circuit of a small he-ne laser demonstration instrument

Related component PDF download:

As shown in the figure, the circuit of a small He Ne laser demonstrator is shown. The utility model has the advantages of small size and free disassembly of the laser tube. It is mainly composed of 12V rectifier power supply, oscillation and boost circuit, He Ne laser tube and shell. The tube of the He Ne laser tube is about 20cm long, with low power, and only tens of milliamperes of current when starting vibration. NE555 integrated circuit and R1, R2, C1, C2 form a non steady state circuit. As long as the power supply is connected, high frequency oscillation can be generated and a large current can be input to the power amplifier tube 3DD15. The amplified oscillation signal is boosted to 200V~300V through transformer, and then rectified by voltage doubling to obtain kilovolt DC high-voltage supply for He Ne laser tube oscillation. The discharge tube is filled with helium neon mixed gas in a certain proportion, and neon atoms emit laser. There are Brewster windows with optical precision machining on both sides of the tube. The two mirrors constituting the resonator are spherical mirrors, whose radius of curvature is slightly greater than the distance between the two mirrors. Brewster window is used to reduce the reflection loss of the laser and enhance the output power of the laser. In the process of photon oscillation in the discharge tube, after encountering the reflector, part of the photon is output, and part of the photon is reflected back to be amplified again. It gets a certain amplification every time it goes back and forth, so that the intensity of light becomes stronger and stronger. The stronger the beam, the more stimulated emission of neon atoms in the excited state. An extremely strong laser beam is output from a partially transmissible mirror.