The output of the laser must be pulsed light

If the drive current pulse current, the output of the laser must be pulsed light. This feature, provides the possibility of direct electrical pulse modulation of the output laser. The impact of temperature on the output power. Can also be seen from Figure 2-3: as the temperature rises, the threshold current Ith increases, the characteristic curve of the laser forward translation with increasing temperature, the laser output power decreased, that may not meet the equipment normal work requirements; as the temperature dropped, the threshold current is decreased, the laser characteristic curve with the temperature dropped back translation, the laser output power rises may eventually burned laser drive current is too large. The threshold current and temperature is basically an exponential relationship can be approximated using the following formula [9]. The laser function of  green laser pointer can be used to point at the star the stargazer wants to observe or show, highlight the content the customer needs to demonstrate and so on.
Where: Ith (T) is the threshold current when the temperature T the Ith0 is the threshold current when the temperature T0, k is the laser related to the constant, T0 is the temperature in the laser room when debugging, generally in the 20 ~ 25 ℃ between the values of T is the laser operating temperature. This feature to the semiconductor laser as a light source equipment in a wide temperature range has brought a lot of trouble. Hardware design of the laser diode driver. Drive power of design ideas. Figure 3-1 shows the block diagram of the power supply, the entire circuit includes a protection circuit, modulation circuit, constant current circuit, temperature control circuit and digital display circuit of five parts. Protection circuit to provide protection for the safe and reliable operation of the LD. The radio frequency wireless presenter  green laser pointer is more popular and widely used.
Modulation circuit is used to make the circuit of constant current circuit output at different frequencies and waveforms; the role of the constant current circuit is the modulated signal of constant voltage signal into a constant current output; temperature control circuit is used to adjust the operating temperature of LD; adjust the control link from to set the parameters of all aspects of adjustment, as well as a variety of feedback signals to make the role of the corresponding processing; digital display circuit for real-time monitoring and instructions on the operating parameters of LD. The power supply block diagram. The high precision and high stability in the design of the laser diode driver. The design of high-precision drive power. Used to generate the modulation waveform signal, there are three direct result of the First, commonly used single-chip the addend mode (A / D) converter chip. Also,  green laser pointer  has some other functions at the same time.
The advantage of this method is simple hardware, complex waveforms can be generated, but by the microcontroller's operating frequency limit, the waveform frequency is low; is the use of the discrete-component signal generation circuit, the advantage is the use of general purpose device of low cost, but the circuit complexity and stability less adjustment difficulties; the use of professional function generator chip, such as the ICL8038, MAX038, these chips are generally only need a few external components can achieve a wide frequency range square wave, triangle wave, sine wave, and other commonly used modulated signals, while the MAX038 ICL8038 than the higher frequency tuning range, and the MAX038 can achieve almost independent of each duty cycle regulation and frequency regulation, so the selection of the MAX038 as the main components of the modulation circuit.   green laser pointer can be used to make the special atmosphere in the special place.