Design of a variable optical attenuator with wavelength selectivity

Abstract

We propose a theoretical design of a high-speed wavelength-selective variable optical attenuator (VOA) constructed by a waveguide-type Raman amplifier and two directional couplers. The VOA can attenuate each incident WDM wavelength individually and simultaneously in a few tens of picoseconds by applying the corresponding pumping wavelength to the Raman amplifier. We define two operation modes, which may allow the attenuation ratio to decrease or increase by increasing the amplification rate of the Raman amplifier. The profile of the attenuation curves of the two operation modes can be flexibly determined by properly selecting the phase angles of the directional couplers. The guidelines to determine these phase angles of the two directional couplers are provided after the operational analyses.

The thermo-optical variable optical attenuator based on SOI

“…Variable optical attenuator (VOA) is an optical passive component which can dynamically control the signal power in the optical domain, and it is mainly used in wavelength division multiplexing (WDM) systems [1,2]. At present VOA's production technologies include micro-electromechanical systems (MEMS) technology and planar light-wave circuits (PLC) technology [3][4][5].…”