We all know that laser diodes are widely used in daily life, so do you know what are their main applications in laser ranging? Let's take a look at it together.

Why do laser ranging almost always use laser diodes?

Because it meets several "hard requirements" of ranging at the same time: fast rising edge (ns level), high-frequency modulation, small size, low power consumption, controllable cost and easy pulse driving, these characteristics are not suitable for xenon lamps, LEDs and solid-state lasers.

Laser diode band commonly used in laser ranging

905nm (most common)

The highest maturity, low cost and the most complete ecology.

850nm

The receiver has high sensitivity and is often matched with silicon photodiode.

940nm

Specific working mode of laser diode in ranging

Pulse emission (mainstream)

Pulse width: tens of ns ~ tens of ns, peak power: tens of watts ~ hundreds of watts (short pulse)

Continuous modulation (phase method)

Continuous light emission and high frequency modulation

Matching device of laser diode in ranging system

A complete ranging and transmitting module, in addition to LD, also includes: high-speed pulse driving circuit, temperature control (some models), collimating/beam-expanding optics, power monitoring photodiode, LD determines the upper limit, and the system determines the performance.

These are the applications of laser diodes in laser ranging. I hope you will have a clear understanding after reading them.