Define the operating point before comparing watts
A headline optical-power value is meaningful only with its drive current, pulse width, duty cycle, temperature and measurement condition. Two arrays advertised at the same wavelength and nominal power can behave very differently in a time-of-flight or structured-light design.
- Peak or continuous optical output
- Pulse width, repetition rate and duty cycle
- Operating and junction-temperature assumptions
- Drive-current waveform and allowed overshoot
Translate the application into a beam requirement
The receiver field of view, working distance and illumination pattern determine whether the source needs a bare array, diffuser, lens or complete module. Ask for far-field distribution and test geometry; a single divergence number may hide asymmetric or multi-lobed behavior.
Review efficiency and heat as a system
Wall-plug efficiency, electrical resistance, driver loss, PCB thermal path and enclosure conditions jointly affect temperature rise. Evaluate the intended pulse train on a representative board instead of extrapolating from a short bench test.
Build a sample request that produces comparable evidence
Give suppliers the same target conditions and request model-level curves, dimensions, optical test conditions and traceability. Then measure every sample with the same fixture and acceptance criteria.
- Target wavelength and tolerance
- Required output at a defined pulse condition
- Beam or field-of-illumination requirement
- Package, footprint and thermal interface
- Quantity stage and destination application