Abstract: An optical switch uses a MEMS device to insert a highly reflective shutter in a gap between a pair of coaxially aligned fibers. When the switch is closed, an input optical signal passes with little loss through the gap. When the switch is open and the shutter is positioned in the gap, an input optical signal incident on the shutter is reflected back into the input fiber. Such light is diverted by an optical circulator into a new path.

Abstract: An optical attenuator for use in optical power regulation uses a shutter to control the insertion loss of a gap in a pair of substantially coaxially aligned waveguides, for example a pair of optical fibers. The shutter is part of a MEMS accuator device and is coupled to the movable one of a pair of spaced plates, the movable plate being movable by a voltage applied between the pair of plates. To regulate the power, a small portion of the optical power is abstracted and used to derive a control voltage that is applied to the optical attenuator for varying the attenuation inserted in the optical wave path.

Abstract: Arrayed waveguide grating routers are used to form 1.times.N demultiplexers and N.times.1 multiplexers to form channel drop modules in a WDM optical network. The demultiplexer and the multiplexer are interconnected by optical waveguides in which are inserted optical switches provided by MEMs devices that can be used to reflect incident optical signals backwards for dropping channels or to both transmit and reflect incident optical signals to drop and detect channels.

Abstract: An integrated optical device (e.g., a wavelength router) is formed on a substrate, where the device has a compressive force within the plane of the device and the substrate has at least one non-straight edge. The device is formed by annealing the substrate wafer and then separating the device by cutting along one or more non-straight or curved lines. When the device layer is much thinner than the substrate and when the coefficient of thermal expansion of the substrate material (e.g., silicon) is greater than that of the device material (e.g., silica), the annealing process generates the compressive force. This in turn enables the device to be separated from a wafer by cutting along non-straight lines using either a laser or a milling machine without fear of cracks and fissures propagating over time into the device. The present invention enables manufacturing with greater yields since curved devices, such as wavelength routers, can be more efficiently packed onto a single wafer.

Abstract: One aspect of the invention is a Fabry-Perot cavity which has in part a waveguiding portion and in part a nonwaveguiding portion. In this manner, a cavity is constructed whose length would be too short to manipulate effectively if it were comprises exclusively of a waveguiding portion, and whose length might have unacceptable diffraction losses if it were comprised exclusively of a nonwaveguiding portion. In the inventive device the resonant wavelength can be adjusted by varying the length of either the gap or the waveguide or both. The device can be advantageously constructed and aligned using fiber coupling technology.

Abstract: This invention is a new type of Fabry-Perot cavity, and an optical communication system using such a cavity. The inventive Fabry-Perot cavity comprises both a waveguiding portion and a nonwaveguiding portion. In this manner, tunable cavities of desirable mid-range length, necessary to obtain required free spectral ranges, may be fabricated with minimal diffraction losses otherwise associated with cavities of such length. The cavity length may be varied using, for example, piezoelectric elements, and the various cavity elements may be aligned and connected, using fiber connector technology.

Abstract: A method for determining crystallographic orientation of an InP substrate wafer includes the steps of immersing at least a portion of the substrate wafer in a chemical etchant for a predetermined amount of time to expose features having a predetermined shape and designating a particular crystallographic direction on the substrate wafer in accordance with relative positions of features on the portion of the substrate wafer.