Night vision monitor for ir laser spot size identification

Abstract EN

The aim of this research is to design and construct a semiconductor laser range finder operating in the near infrared range for ranging and designation.

The main part of the range finder is the transmitter which is a semiconductor laser type GaAs of wavelength 0.904 μm with a beam expander and the receiver ; a silicon pin detector biased to approve the fast response time with its collecting optics.

The transmitters pulse width was 200ns at a threshold current of 10 Ampere and maximum operating current of 38 Ampere.

The repetition rate was set at 660Hz and the maximum operating output power was around 1 watt.

The divergence of the beam was 0.268o the efficiency of the laser was 0.03 % at a duty cycle of 1.32x10-4.

Special software (ZEMAX EE 2000) was implemented for optimum optical design.

The transmission and reflection of the laser pulse spot size were observed and detected by a Night Vision Monitor of second generation with fast digital camera.

The Mat lab software used is capable of analyzing and displaying the profile in 4 different methods that is, color code intensity contouring, intensity threshold intensity cross section along two dimensions x-y and three dimensional plot of the beam intensity given in the same display.

The atmospheric attenuation for this semiconductor laser was also calculated using Low- Tran .6 code, which indicated that negligible attenuation is recorded below 2 Km range for 0.904.

= ג μm