Title :
Measurement of gain in pump diode lasers using a low-coherence source and synchronous detection
Author_Institution :
Bookharn Technol. AG, Zurich, Switzerland
Abstract :
A novel method for determining gain in long-cavity Fabry-Pe´rot diode lasers is presented. Gain is extracted from a return-loss measurement via a simple model. The experimental setup is based on the injection of a low-coherence probe signal into the laser cavity and synchronous detection of the reflected light. Using a fiber-optics setup, gain can be determined in commercial fiber-coupled laser modules. The novel technique is particularly suitable for diode lasers with very long cavities. To illustrate the method, the gain spectra of a 980-nm pump diode laser with 1800-μm cavity length are determined. Gain saturation due to probe signal injection is addressed.
Keywords :
laser cavity resonators; laser variables measurement; light reflection; light sources; optical design techniques; optical fibre couplers; optical pumping; semiconductor lasers; 1800 mum; 980 nm; Fabry-Perot diode lasers; fiber-coupled laser modules; gain spectra; laser cavity; light reflection; low coherence source; probe signal injection; pump diode laser; return-loss measurement; synchronous detection; Diode lasers; Fiber lasers; Gain measurement; Laser excitation; Laser feedback; Laser modes; Optical pumping; Probes; Pump lasers; Stimulated emission;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2003.822711
