It is the high cost performance of laser pointer

It is the high cost performance of laser pointer .
Therefore, the high-end laser transmitter to be used for two-way temperature control. Laser cooling, at room temperature and high temperature environment in the low-temperature environment of the laser rapid heating to reach thermal equilibrium. Users should pay attention to buy the transmitter to identify the optical transmitter is a two-way temperature control technology, especially in the winter cold in northern regions. Automatic power control (APC) circuit unit. The existence of the error, automatic temperature control semiconductor laser aging over time to the laser output power given partial shed decline is inevitable, in order to maintain a constant transmit power of the optical transmitter, the laser automatic power control circuit, for low threshold current uncooled laser. We all know that direct modulation of the optical transmitter is using high-frequency television signals directly drive the laser tube, making the light output intensity varies with the changes of the RF signal strength.
If some manufacturers of optical transmitter pre-distortion circuit, it really is to save can no longer save. Branch detection irradiating machine, its role is to detect the optical transmitter drive level, the location of the point of substantially different RF detection of the optical transmitter is not the same, and some on the variable attenuator module However, the best location should be pre-distortion circuit and the laser, this position detection is most accurate. Early in the optical transmitter and some simply dispense with the RF excitation circuit, leaving only an adjustable attenuator and pre-distortion circuit, this optical transmitter requires a high signal circuit input, and now the market has rarely met. The drive structure of the dual module, the circuit of such a structure, two amplifier module to drive the RF signal. The block diagram below. USB flash disks can be added to the receivers of laser pointer of this kind.
Economic models of most manufacturers have adopted this structure, the preamplifier is generally a low-noise push-pull amplifier module, amplification module gain is generally 14-18dB; not put the power doubler amplifier module, the module gain is generally 18-20dB . From a structural point of view of the RF driver circuit with ordinary two-module dry put the same structure, in order to ensure that the optical transmitter carrier to noise ratio indicator, the gain can not be too high (the minimum amplifier input level to determine the method through analysis), the net gain usually in the 25-28dB. This circuit before class low-noise push-pull amplification, relative to the first circuit, the only downside is to gain control using a variable attenuator. A better production of laser pointer can be provided.