High-tolerance broadband-optical switch in planar lightwave circuits

Abstract

The invention relates to a broadband optical switch with a couple of asymmetric wave guide insulation couplers, the asymmetric wave guide has a curvature variable part, the broadband optical switch comprises two insulation couples with a two multiple two structure based on Mach-Zehnder interferometer and an insulation couple with an one multiple two structure, or a Y splitter with a two multiple one structure. Each insulation couple comprises two wave guide branches with different but constant width and two symmetric wave guide branches; wherein, the two wave guide branches are provided with variable radial bend, by changing the distance between the two wave guide branches, enabling to separate the two wave guide branches within the couple length, and mixed in asymmetric crossed area.. In two multiple two switches, two insulation couplers are faced to each other along the main propagation axis in the way of mirror image via the counterpart symmetric branch, and connected with the same two arms.The insulation coupler with variable curvature is used in the silicon dioxide MZI switch on the silicon substrate, which provides the switch with a special bandwidth range (1.2-1.7 Mum), high extinction ratio (more than 35dB), low manufacture sensitivity and operations having nothing to do with polarization. The broadband optical switch has the advantages of more compact size compared with known broadband switches, less extra loss, and faster switching time and lower power consumption.

Description

[0001] This application is a continuation-in-part of US Patent Application No. 10 / 098,391, filed February 18, 2002, which claims priority to US Provisional Application No. 60 / 341,240, filed December 20, 2001. Background technique [0002] The rapid growth of modern telecommunications has created an increasing need for fast and efficient ways of rout information between multiple users. As fiber optics replace older copper wires, there is a growing need for low-cost directional (direct) optical switches. Such optical switching elements should be used in modern communication network systems supporting dense wavelength division multiplexing (DWDM) for various applications such as optical add-drop multiplexing (OADM), optical cross-connect (OXC), protection, restoration, etc. operate in. [0003] To achieve higher capacity, more communication channels are required. Therefore, a wider bandwidth of optical components is necessary. Such broadband components must be mass-produced at...

AI Technical Summary

Problems solved by technology

These couplers and MZI switches have several disadvantages: they have to be very long for thermal insulation, and the coupling effects of the small (few micrometers) gap between the coupler's waveguides are critical for fabrication (e.g. for overetching, material stress, etc. ) are very sensitive, resulting in a lower extinction ratio, or a narrower operating wavelength window

Under usual manufacturing conditions, the ER in the spectral range of 1.25-1.6 μm is only 15dB, which is also insufficient for most current applications

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