Abstract: A collimator array is disclosed that carries forward its alignment characteristics to optical devices that incorporate it. Little, if any active alignment need be performed in the manufacturing of such optical devices, such as switching arrays and optical add/drop arrays that employ a plurality of such collimator arrays in each device. The collimator array includes a fiber array having a plurality of regularly spaced optical fibers such that an output axis of each optical fiber has a predetermined spatial position and orientation with respect to a reference edge of the fiber array. The collimator array also includes an array of lenses separated from the fiber array by an air gap and aligned with the fiber array at an alignment position. The aligned position is such that collimated light exiting each lens has a predetermined position and direction with respect to the reference edge of the fiber array.

Abstract: A tap coupler device for an optical array is formed either in a waveguide structure or in a V block in which a fiber array may be mounted. The tap coupler device may include a substrate with main and tap waveguides formed therein, and waveguide tap couplers formed in the substrate for diverting a portion of the optical signal from the main waveguides to corresponding tap waveguides. Another variation includes a substrate including waveguides, with the surface of the substrate where the waveguides end inclined to reflect a portion of the signals in the waveguides toward the top surface of the substrate. Yet another variation includes an input V block having input fibers. The surface of the V block where the input fibers terminate is inclined to reflect a portion of light signals from the input fibers toward the top surface of the V block.

Abstract: A collimator array is disclosed that carries forward its alignment characteristics to optical devices that incorporate it. Little, if any active alignment need be performed in the manufacturing of such optical devices, such as switching arrays and optical add/drop arrays that employ a plurality of such collimator arrays in each device. The collimator array includes a fiber array having a plurality of regularly spaced optical fibers such that an output axis of each optical fiber has a predetermined spatial position and orientation with respect to a reference edge of the fiber array. The collimator array also includes an array of lenses separated from the fiber array by an air gap and aligned with the fiber array at an alignment position. The aligned position is such that collimated light exiting each lens has a predetermined position and direction with respect to the reference edge of the fiber array.

Abstract: An assembly that could be used either as a switch or an attenuator includes two or more optical channels defined by lithography within a substrate. The two or more optical channels are positioned so that the ends of the optical channels are at or near an edge of the substrate. A moveable MEMS mirror is positioned near the edge of the substrate and the openings, with the face of the mirror positioned to receive an optical signal from one of the optical channels. The mirror can direct an optical signal from one of the optical channels into another of the optical channels. Mirror position can be changed to alter the path of the optical signal and to change the coupling between the optical channels. In this way, the assembly of optical channels within the substrate and the MEMS mirror can act as a switch or as an attenuator.

Abstract: An isolation method for a single crystalline silicon microstructure using a triple layer structure is disclosed. The method includes forming the triple layer composed of an insulation layer formed over an exposed surface of the silicon microstructure, a conductive layer formed over the entire insulation layer, and a metal layer formed over a top portion of the microstructure; and partially etching the conductive layer to form electrical isolation between parts of the microstructure. The method does not require a separate photolithography process for isolation, and can be effectively applied to microstructures having high aspect ratios and narrow trenches. Also disclosed are single crystalline silicon microstructures having a triple layer isolation structure formed using the disclosed method.

Abstract: A tap coupler device for an optical array is formed either in a waveguide structure or in a V block in which a fiber array may be mounted. The tap coupler device may include a substrate with main and tap waveguides formed therein, and waveguide tap couplers formed in the substrate for diverting a portion of the optical signal from the main waveguides to corresponding tap waveguides. Another variation includes a substrate including waveguides, with the surface of the substrate where the waveguides end inclined to reflect a portion of the signals in the waveguides toward the top surface of the substrate. Yet another variation includes an input V block having input fibers. The surface of the V block where the input fibers terminate is inclined to reflect a portion of light signals from the input fibers toward the top surface of the V block.

Abstract: An optical ON/OFF switch includes a micro-mechanical shutter formed on a silicon substrate using micro-mechanical fabrication techniques. The switch selectively opens and closes an optical path between two fibers with the micro-mechanical shutter. A micro-mechanical latch latches the shutter open or closed and remains in this state until electrical signals disengage the latch. Incoming and outgoing fibers are coupled to the shutter within the switch so that, when the shutter and the switch are ON (open) light couples between the ends of the two fibers. The fibers are positioned within stepped channels that hold each fiber along two edges within the channels so that the fibers are held in fixed alignment and relation. The fibers are laterally offset with respect to each other and the faces of the fibers are angled to limit back reflections from the shutter while still obtaining good coupling between the fibers.

Abstract: An assembly that could be used either as a switch or an attenuator includes two or more optical channels defined by lithography within a substrate. The two or more optical channels are positioned so that the ends of the optical channels are at or near an edge of the substrate. A moveable MEMS mirror is positioned near the edge of the substrate and the openings, with the face of the mirror positioned to receive an optical signal from one of the optical channels. The mirror can direct an optical signal from one of the optical channels into another of the optical channels. Mirror position can be changed to alter the path of the optical signal and to change the coupling between the optical channels. In this way, the assembly of optical channels within the substrate and the MEMS mirror can act as a switch or as an attenuator.

Abstract: An optical add/drop module includes an add channel, an input channel, a drop channel and an output channel, with each channel aligned to transmit or receive light reflected from a common mirror in at least one state of the add/drop module. Rotating the mirror changes the state of the module. In the module's add/drop state, light from the input channel reflects from the mirror into the drop channel and light from the add channel reflects off the mirror to the output channel. In the module's pass through state, light from the input channel reflects off the mirror into the output channel and light from the add channel reflects off the mirror to a position other than the drop channel. Arrays of add, input, drop and output channels can be coupled to a linear array of independent micro-electromechanical mirrors to provide an integrated set of optical add/drop modules.

Abstract: An optical add/drop module includes an add channel, an input channel, a drop channel and an output channel, with each channel aligned to transmit or receive light reflected from a common mirror in at least one state of the add/drop module. Rotating the mirror changes the state of the module. In the module's add/drop state, light from the input channel reflects from the mirror into the drop channel and light from the add channel reflects off the mirror to the output channel. In the module's pass through state, light from the input channel reflects off the mirror into the output channel and light from the add channel reflects off the mirror to a position other than the drop channel. Arrays of add, input, drop and output channels can be coupled to a linear array of independent micro-electromechanical mirrors to provide an integrated set of optical add/drop modules.

Abstract: An electrical isolation method for silicon microelectromechanical systems provides trenches filled with insulation layers that support released silicon structures. The insulation layer that fills the trenches passes through the middle portion of the electrodes, anchors the electrodes to the silicon substrate and supports the electrode. The insulation layers do not attach the electrode to the sidewalls of the substrate, thereby forming an electrode having an “island” shape. Such an electrode is spaced far apart from the adjacent walls of the silicon substrate providing a small parasitic capacitance for the resulting structure. The isolation method is consistent with fabricating a complex structure or a structure with a complicated electrode arrangement. Furthermore, the structure and the electrode are separated from the silicon substrate in a single release step.

Abstract: A true vertical mirror is made in silicon along a vertical crystal plane of silicon. The method of making the mirror includes forming a mask on a (110) silicon surface so at least a portion of the mask is substantially aligned along an intersection between the (110) surface plane and a vertically extending (111) silicon plane. The mask is a layer of silicon oxide to facilitate a deep etching process. Vertical etching proceeds from the (110) surface substantially along the vertically extending (111) plane to form a first surface extending away from the (110) surface of the silicon. Lateral etching of the first surface creates a mirror-quality surface parallel to a vertically extending (111) crystalline plane. Advantageously, the lateral etching can be performed using an alkaline solution that tends not to etch the (111) face of silicon.

Abstract: An optical ON/OFF switch includes a micro-mechanical shutter formed on a silicon substrate using micro-mechanical fabrication techniques. The switch selectively opens and closes an optical path between two fibers with the micro-mechanical shutter. A micro-mechanical latch latches the shutter open or closed and remains in this state until electrical signals disengage the latch. Incoming and outgoing fibers are coupled to the shutter within the switch so that, when the shutter and the switch are ON (open) light couples between the ends of the two fibers. The fibers are positioned within stepped channels that hold each fiber along two edges within the channels so that the fibers are held in fixed alignment and relation. The fibers are laterally offset with respect to each other and the faces of the fibers are angled to limit back reflections from the shutter while still obtaining good coupling between the fibers.

Abstract: An isolation method for a single crystalline silicon microstructure using a triple layer structure is disclosed. The method includes forming the triple layer composed of an insulation layer formed over an exposed surface of the silicon microstructure, a conductive layer formed over the entire insulation layer, and a metal layer formed over a top portion of the microstructure; and partially etching the conductive layer to form electrical isolation between parts of the microstructure. The method does not require a separate photolithography process for isolation, and can be effectively applied to microstructures having high aspect ratios and narrow trenches. Also disclosed are single crystalline silicon microstructures having a triple layer isolation structure formed using the disclosed method.

Abstract: An electrical isolation method for silicon microelectromechanical systems provides trenches filled with insulation layers that support released silicon structures. The insulation layer that fills the trenches passes through the middle portion of the electrodes, anchors the electrodes to the silicon substrate and supports the electrode. The insulation layers do not attach the electrode to the sidewalls of the substrate, thereby forming an electrode having an “island” shape. Such an electrode is spaced far apart from the adjacent walls of the silicon substrate providing a small parasitic capacitance for the resulting structure. The isolation method is consistent with fabricating a complex structure or a structure with a complicated electrode arrangement. Furthermore, the structure and the electrode are separated from the silicon substrate in a single release step.