Here will introduce the life time of green laser pointer

Pulsed laser ranging system design. Laser ranging to the use of the laser pulse toward the target to measure the target distance of a distance measuring instrument. Pulsed laser ranging divergence angle of the laser, the laser pulse duration very short, the great instantaneous power (up to MW), and thus enable the laser ranging system has a good direction, high-ranging accuracy and measurement range far, the strong anti-interference ability, good for hiding, etc., has been widely used in the military field. At present, many types of laser ranging system, divided into pulses ranging method, phase three categories ranging law and interference in the ranging method. Compared to the pulsed laser ranging phase laser ranging method has the following advantages. Especially when the customer adjusts the focus of this kind of   green laser pointer   .
First, the same total average optical power output of the pulsed laser laser range finder to measure the distance will be far continuous wave laser rangefinder longer. Second, the the Ranging faster. Does not require cooperation objectives, concealment and security. Consider the above characteristics and the actual system design to meet the characteristics of small size, low power, high repetition rate, ranging fast pulsed laser ranging as a whole system ranging in this experiment. Typical optoelectronic information systems - laser ranging system design and implementation, to understand the composition of the common photoelectron information systems, to grasp the general design of the typical optoelectronic information system. The energy of the laser beam emitted by    laser pointer   can be concentrated within a very narrow range.
Hardware modules to build an indoor simulated laser ranging system, the preparation of the microcontroller program to calculate the distance measuring distance and display simulated indoor laser ranging. Pulsed laser ranging system, the principle of the microwave pulse radar ranging principle is similar, ranging point to the measured target to launch a bunch of short, strong laser pulses, optical pulse emission to the target a small portion of laser reflectors to distance measuring point receiver of the optical functions. Set the target distance R, the laser pulse to and from the elapsed time t, the speed of propagation of light in air is c, then the distance measurement formula is as follows: R = ct / 2. The actual pulse laser rangefinder is the use of the clock crystal oscillator and pulse up and measurement time interval t. The laser range of this kind of    green laser  can reach 800m at least.
Crystal oscillator clock is used to generate a fixed frequency electrical pulse oscillation (T = 1 / f) the role of the pulse counter to count the number of electrical pulses generated in the crystal. Such as the number of pulses in the light round-trip time between the rangefinder and the target t is N, the energy band measured distance R ==. Relative ranging accuracy. Figure: System composition and demonstration of the overall program. Pulsed laser ranging system consists of three parts: the laser transmitter, laser receiver part and the signal processing section. First semiconductor laser emission of a laser pulse, the laser pulse collimated after launch optical system toward the target (in this experiment, the laser propagation through a period of fiber), sampling a small part of that thoroughly remove the main wave is sent as a reference pulse in the main wave into the receiving system. It is very useful and practical for the customer to use this kind of green laser led  in the open air.
Photodetector is converted into electrical impulses, and then open the gate amplifier, then the counter starts counting. After some time, the target launch back echo pulse signal (in this experiment, the fiber propagation signal) by the convergence of the receiving optical system, hitting the detector, after the photoelectric conversion and amplification into electrical signals enter the gate, the gate closed, the counter stops counting. In this way, open the door to the closed counter into the N pulses can be measured by the length of this fiber R = Nc/2f.  green laser pointer  can be used to point out the direction for the client.