Byong-Jin Ma

All-optical switching in a distributed-feedback GaInAsP waveguide.

The characteristics of all-optical switching in a waveguide device with a distributed-feedback structure were experimentally investigated. The device was composed of a strip-loaded GaInAsP/InP waveguide and a distributed-feedback structure, which was fabricated by a combination of reactive-ion etching and electron-beam exposure. In the experiments, several optical switching operations were demonstrated. In particular, the all-optical set-reset operation and threshold operation were obtained.

GaInAsP-InP distributed feedback waveguides for all-optical switching

All-optical switching characteristics of waveguide devices having a nonlinear distributed feedback structure are reported theoretically and experimentally. These devices were composed of a strip-loaded GaInAsP-InP waveguide and a Bragg reflector, which were suitable for optical integrated circuit. In the experiments, all-optical and gate operation and set-reset operation for two output ports were successfully demonstrated.

Realization of all-optical wavelength converter based on directionally coupled semiconductor optical amplifiers

We propose a novel all-optical wavelength converter based on directionally coupled (DC) semiconductor optical amplifiers (SOA) and simulate its characteristics using a simple model to find out such advantages as extinction enhancement and digital response. We then fabricate devices in the 1.55 /spl mu/m band, and successfully demonstrate the wavelength conversion operation with the above-mentioned advantages. Very compact size and no need of active/passive integration are other significant merits of DC SOAs.

Dependence of Threshold Switching Power on the Control-Light Wavelength in a Nonlinear Distributed-Feedback GaInAsP Waveguide.

We demonstrate all-optical bistable switching by using orthogonally and parallelly polarized control light in a nonlinear distributed feedback GaInAsP waveguide. When the control light that is orthogonally polarized to the signal light is within its stopband, it is possible to extract the signal without using any external devices. Also, we investigate theoretically and experimentally the dependence of threshold switching power on the wavelength and polarization of control light.

Demonstration of all-optical AND gate operation in a GaInAsP waveguide

In the present paper an all-optical AND gate operation in a nonlinear DFB waveguide monolithically integrated with a Y-coupler is reported. It is concluded that the device does exhibit optical AND gate operation due to the intensity-dependent nonlinearity.

Novel all-optical wavelength converter using coupled semiconductor optical amplifiers

The wavelength converter has been considered to be one of the key devices in wavelength division-multiplexed (WDM) systems because it allows reuse of wavelengths, thus avoiding wavelength channel contention and giving more flexibility to the systems. Although several wavelength converters exist, problems such as insufficient conversion efficiency and critical operating conditions have prevented them from being widely deployed. In this paper, we describe a type of semiconductor wavelength converter with compact size and better conversion characteristics. The newly proposed wavelength converter utilizes coupled semiconductor optical amplifiers (SOAs) and has a very simple structure.

Dependence of control light wavelength in all-optical switching of nonlinear strip-loaded distributed feedback waveguide

In this paper, all-optical switching operation using orthogonally and parallelly polarized control light for TE-polarized signal is experimentally investigated in the strip-loaded distributed feedback waveguide. In addition, the relation between threshold switching power and control light wavelength is investigated.

All-optical wavelength conversion based on Fabry-Perot semiconductor optical amplifier

Summary form only given. An all-optical wavelength converter is one of the key components in wavelength-division multiplexed (WDM) systems because it allows reuse of wavelength resources and prevents wavelength channel contentions. Fabry-Perot semiconductor optical amplifiers (FP-SOAs) have potential to be used as all-optical switching and optical flip-flop devices. They are attractive not only due to simple fabrication without anti-reflection coating step or active/passive integration but also due to their signal amplification capability and very strong nonlinearity. We demonstrate a new all-optical wavelength converter based on the FP-SOA.

Demonstration of all-optical switching in a GaInAsP distributed feedback waveguide

All-optical threshold operation and set-reset operation are successfully demonstrated in a GaInAsP waveguide with a Bragg reflector. In order to integrate the bistable device with other optical functional devices, it is the most promising way to use distributed Bragg reflectors for optical feedback. An intensity-dependent Bragg condition derives all-optical switching in a Bragg reflector-loaded waveguide having an intensity-dependent refractive index.

Proposal of photon-induced waveguides for all-optical switching and wavelength conversion

A photon-induced waveguide (PIG) utilizing switching between guiding and antiguiding is proposed and analyzed. The PIG has a similar structure as the conventional ridge-waveguide semiconductor optical amplifier (SOA). The only difference is that the PIG has a very slight refractive index step between the waveguide region and the background region.