Cross talk reduction in switching networks by asymmetrical off-on switches

Bernhard, Winfried; Mueller-Fiedler, Roland; Pertsch, Thomas; Waechter, Christoph A.

doi:10.1117/12.343744

Cited by 4 publications

(1 citation statement)

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“…Variable optical attenuators, or VOAs, are required for the reduction of crosstalk in switching networks [1], the moderation of power fluctuations {2], and the equalization of channel power levels in wavelength multiplexed systems [2]. Several technologies have been utilized to demonstrate efficient VOAs, and they can be separated into two major categories: Those technologies that are adequate for free-space communications, and those devices applicable to photonic integrated circuits (PICs).…”

Section: Introductionmentioning

confidence: 99%

<title>Variable optical attenuator using active multimode interference waveguide</title>

et al. 2004

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We propose a new structure for an integrated variable optical attenuator using InGaAsP multiple quantum wells. The principle of operation relies on the self-imaging properties of multimode interference (MMI) waveguides. The device consists ofa MMI region that is 12 tm wide by 350 tm long, with input and output waveguides that are 2 im wide. The dimensions ofthe MMI are calculated such that an image ofthe input field is produced at the output waveguide. The last statement is true as long as the phase relation between the modes in the MMI section is kept constant. Therefore, by selectively perturbing the refractive index within the MMI section, the phase relation of the modes is altered, thereby modifying the interference properties at the output of the device. We present numerical simulations using the FiniteDifference Beam Propagation Method (FD-BPM), and demonstrate that optical attenuation is possible by selectively modulating the refractive index of a narrow region within the MMI section. A dynamic range of -37 dB can be easily obtained at a wavelength of 1.55 tm with a device insertion loss of 0.3 dB. The effects of electro-absorption on the device performance are also investigated.

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Section: Introductionmentioning

confidence: 99%