Knowledge
Engineering knowledge base
The physics, trade-offs and failure modes behind laser source selection - written for people who have to commit to a design.
Selection guide
Deciding between options that both look reasonable on a datasheet.
905 nm vs 1535 nm vs 1550 nm: choosing a wavelength for ranging and LiDAR
The wavelength decision sets your detector, your eye-safety class, your maximum usable energy and your weather performance. Here is how the three bands actually compare for ranging work.
Selection guideHow to choose a 905 nm pulsed laser diode: from range target to part number
A repeatable procedure for turning a range requirement into pulse energy, pulse energy into peak power and pulse width, and peak power into the smallest package that survives your duty cycle.
Selection guidePeak power, pulse width and duty cycle: the three numbers that define a pulsed laser diode
Peak power sells the part, pulse width sets the resolution, and duty cycle decides whether it survives. Getting the relationship wrong is the most common way a pulsed laser design fails.
Selection guideVCSEL vs edge-emitting laser: choosing a source for 3D sensing and LiDAR
Edge emitters win on peak power and range, VCSELs win on beam shape, duty cycle and cost. The comparison that matters is not watts - it is pulse energy, and the two technologies reach it in completely different ways.
Detectors
The receive side, where most of a link margin is won or lost.
Optics
Getting the beam from the die to the target.
Fast-axis collimation and fibre coupling: getting the beam from the die to the target
An edge emitter's 25 degree fast axis wastes most of its energy on empty sky. Here is what a fast-axis collimator actually recovers, why it is a precondition for fibre coupling, and when you should not use one.
OpticsVisible and RGB laser illumination: brightness, white balance and speckle
A visible source is not a 905 nm part with a shorter wavelength. The photopic curve decides which colour owns the power budget, etendue decides how bright the spot can be, speckle decides how uniform it looks - and the eye's aversion response changes the safety arithmetic, but less than most people assume.
Safety
What the standards require, and what they mean for your energy budget.
Physics
The relationships that constrain every laser ranging design.
Electronics
Driving a laser diode without destroying it.