We demonstrated that the wavelength range of lasing generated in optical loop amplifiers can be controlled by varying the reflection wavelength range of an add/drop filter. Controlling the lasing wavelength range enabled the gain to be precisely controlled relative to the input wavelength. The ring-down pulse waveform exhibits similar behavior to an optical memory when the lasing region is close to the input wavelength and it is exponentially attenuated when the region is far from the input. When the optical loop memory effect is optimized, a 200 ns optical pulse can be retained in the memory for 20 μs.
Semiconductor optical amplifier (SOA) module, RSOA, SOA with mirror has become an essential component to be at
the head of negative feedback amplification effect, optimum gain, and cross-gain modulation with demand for longer
transmission lengths. The SOA module is expected to have an advantage of exhibiting much faster negative feedback
(NF) response because distance of optical signal passing through component to component is shorten than system
connected with fibers. Scattered degree and baseline line difference of eye-pattern diagrams demonstrated that NF effect
can be compensated compactness and stability from band pass filter in SOA module. Modulation degree (MD) of input
and output signals confirmed that SOA module with NF effect can be stabilized gain and waveguide of output signal and
reduced a wave distortion as well as consistent with results in eye-pattern waveform and bit error rate (BER). All-optical
switching triode with SOA module was realized in about 60 % output modulation degree at control power range of 0.01
to 1 mW. We propose that our manufactured SOA module become strong component candidate to realize all optical
switching triode with NF effect for high speed optical processing in next generation.