A laser diode is a laser where the active medium is a semiconductor similar to that found in a light-emitting diode. The most common and practical type of laser diode is formed from a p-n junction and powered by injected electric current. The laser cavity has mirrors at each end to reflect back and forth photons to create an amplification effect when the waves are in phase. At certain frequencies a stable standing wave pattern is formed. At these frequencies the cavity is in resonance, and the oscillation can be sustained with minimum losses.
At resonance, an integral number of half wavelengths of the resonating wavelength of the resonating wave must fit into the light of the cavity:
L = mλ/2
L = length of the cavity (m)
m = an integral
λ =wavelength of the resonating frequency (m)
Pulsed semiconductor lasers in the near IR (NIR) are commonly used for long distance time-of-flight or phase-shift range finding systems. Warsash Scientific offer a broad range of suited pulsed 905 nm lasers including monolithic layered structures with up to 4 active areas per chip, resulting in up to 100 Watts of peak output power.Send Enquiry
Infrared Emitting Diodes (IRED) are typically used in conjunction with Excelitas detectors to form a sensing system. IREDs with wavelengths 770 nm, 870 nm 880 nm, 940 nm, and 950 nm are offered for applications like Smoke Detection, Encoders, Transmissive and Reflective Optoswitches.
LEDs are solid state p-n junction devices which emit light when forward biased. An LED is a Light Emitting Diode, a generic term. An IRED is an Infrared Emitting Diode, a term specifically applied to Excelitas IR emitters. Unlike incandescent lamps which emit light over a very broad range of wavelengths, LEDs emit light over such a narrow bandwidth that they appear to be emitting a single "colour". Their small size, long operating lifetimes, low power consumption, compatibility with solid state drive circuitry, and relatively low cost, make LEDs the preferred light source in many applications.Send Enquiry