Experimental Design for Laser Wavelength Tuning by Mixed Feedback and Injection

Experimental validation of new simple technology for narrow-linewidth and wavelength-tunable lasers is carried out. The method is based on the use of nonlinearities that occur as a result of mixed both laser optoelectronic feedback (OEFB) and optical injection (OI). From several nonlinearities, the main effect observed and controlled is Mode Hopping (MH). Mixing these two effects gave the facility for changing the initial conditions for the chaotic effects. It boosts the slave laser's modulation index to 100% and uses MH generated in it to tune the output lasing frequency. This is accomplished by controlling either master laser detuning or injection strength, or both. Also, by injecting a nonlinear function into the detected signal and adjusting the slave laser OEFB time delay (through a variable attenuator) or (and) nonlinear contribution for this. Results show a simpler setup where no need of using a Fiber Bragg Grating filter, which is the common technique used to build a tunable laser.