Optical Bistability in a Traveling-Wave SOA Connected to a DFB Laser Diode: Theory and Experiment

Abstract

Abstract-The behavior of two types of gain-clamped semiconductor optical amplifiers under small-signal optical modulation is analyzed both numerically and experimentally. The small-signal gain as well as the crosstalk is investigated in two different injecting schemes. Dependence on mean input power and signal frequency is studied. The study reveals a strong dependence of the small-signal gain on the direction of the data signal as compared to the pump signal. The biggest difference between both amplifier types is found in the co-propagation scheme where the RF gain shows a clear resonance in the case the gain clamping is achieved by a longitudinal laser field which results in a decrease of the small-signal gain around the resonance frequency. The behavior of the crosstalk is similar in both cases, however still showing differences due to the origin of the gain clamping, which will be discussed. The experiments confirm the results found in the numerical study in all cases.Index Terms-All-optical devices, gain-clamped semiconductor optical amplifier (GCSOA), linear optical amplifier, SOA, smallsignal analysis.

All-Optical Flip-Flop Based on an SOA/DFB-Laser Diode Optical Feedback Scheme

“…Previously we reported static bistable operation of a semiconductor optical amplifier (SOA) bidirectionally coupled to a distributed feedback laser diode (DFB-LD) [7]. In addition to that, dynamic simulations showed that the device can also be used as an AOFF, i.e., can be set and reset using optical pulses [8].…”

“…When a continuous-wave (CW) beam is injected at the SOA side, it has been shown that bistable operation can occur with the actual state depending on the history of the device [7]. The two stable states are defined as either the state where the laser diode is switched ON or the state where the laser diode is switched OFF.…”

Flip-flops ópticos basados en interferómetros Mach-Zehnder activos con realimentación

“…En [Oos06] se propone interconectar un SOA con un DFB-LD (DFB-Laser Diode). La configuración de [Kim04] es muy similar porque se basa en un SOA/DFB-SOA pero utiliza el SOA sólo como amplificador.…”

“…En la Fig. 2.17 se muestra el esquemático del flip-flop de [Oos06]. Al acoplar un SOA con un DFB-LD son posibles dos estados estables de funcionamiento.…”