8km Laser Range Finder Module

a)Working temperature：-40℃～+60℃。
b)Storage temperature：-45℃～+70℃。
C)Random vibration: 15～2000Hz, 3 directions. The specific test conditions are shown in Table 1.
Table 1 Random vibration test conditions

The impact test conditions are shown in Table 2.

The M0408X is designed for system integrators looking for a convenient, powerful and compact laser ranging solution. It provides reliable performance in a wide range of applications.

It is very small, ultra-light, has low power consumption and can be measured over a long distance. It is suitable for handheld devices (thermal imaging), weapon mounting applications, portable systems and lightweight sensor suites and unmanned aerial vehicles or UGVs.

Targets and condition requirements
Visibility≥8km
Humidity≤80%
For vehicles with 2.3m×2.3m dimension
Reflectivity=0.3
Ranging ability≥4km

Analysis and verification
The main parameters that affect ranging ability are peak power of lasers, divergence angle, transmitting and receiving transmittance, wavelength of laser, etc.
For this laser rangefinder, it takes ≥40kw peak power of lasers, 0.5mrad divergence angle, 1535nm wavelength, transmitting transmittance≥90%, receiving transmittance≥80% and 25mm receiving aperture.
It is a laser rangefinder for small targets, ranging ability can be calculated by the following formula. Ranging formula for small targets：



: Detectable optical power
: Transmitting power of laser rangefinder(40kw)
: Transmitting transmittance(0.9)
: Receiving transmittance(0.8)
: Optical receiving area(25mm receiving aperture)
: Effective reflection area of targets(5.29㎡)
: Target reflectivity(0.3)
: Atmosphere attenuation coefficient(0.2)
: Visibility(according to testing condition)
: Distance to targets

As long as detectable optical power that reflected by targets is larger than minimum detectable power, a laser rangefinder is able to range distance to a target. For a laser rangefinder with 1535nm wavelength, generally, the minimum detectable power(M.D.S) of APD is 5×10-9W.
Under 8km visibility with 6km distance to targets, the minimum detectable power is almost close to M.D.S of APD(5×10-9W), therefore, under a condition with 8km visibility, a laser rangefinder can range distance for (2.3m×2.3m) targets up to 6km(might be close or less than 6km).