Abstract: A microstructure is provided which facilitates alignment by allowing movement of the microstructure between one of a plurality of positions. The microstructure is included in an electromechanical machine which comprises a base layer, an actuator and two or more structural plates. One of the structural plates can be deflected to select a movement limit for the other structural plate. Methods for configuring the structural plates relative to each other to facilitate alignment are also provided.

Abstract: A number of methods and systems for overcoming stiction are provided. The systems include electromechanical systems capable of exerting a variety of forces upon areas prone to stiction. The systems can be MEMS arrays or other types of devices where stiction related forces occur. The methods include a variety of ways of causing movement in areas prone to stiction forces. Such movement can be vibrational in nature and is sufficient to overcome stiction, allowing a trapped element to be moveed to a desired location.

Abstract: A configuration is provided by which it may be determined whether a MEMS device is in a select state. The select state is defined by a position of a moveable element, which is moved with electrostatic forces upon activation of an electrode. The select state is detected with a sensing configuration that has first and second regions. The regions are generally separated such that they are electrically uncoupled unless the moveable element is in the position that defines the select state. A detector may be provided to indicate whether the first and second regions are coupled electrically.

Abstract: The present invention provides improved MEMS devices and methods for use with fiber-optic communications systems. In one embodiment, an apparatus for steering light has a beam layer (160) with a reflective surface. The device uses a multi-layer electrode stack underlying the beam layer to rotate the beam layer into a desired position. Additionally, an underlying rotation and support structure provides a stable platform for the beam layer when the device is activated. In one embodiment, the underlying structure provides a multi-point landing system to maintain a generally flat beam layer upper surface when the device is activated.

Abstract: A method and system are provided for operating an array of such optical micromirrors. Electrodes associated with each of a plurality of optical micromirrors within the array are sequentially actuated by applying a voltage to each such electrode for a fixed time. The voltage applied to each of the electrodes is selected so that the optical micromirror with which that electrode is associated is positioned in a certain tilted position. The step of sequentially actuating electrodes is repeated to maintain the tilted positions of the plurality of optical micromirrors.

Abstract: A wavelength router is provided that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input port and the output ports. The free-space optical train may include air-spaced elements or may be of generally monolithic construction. The optical train includes a transmissive dispersive element, such as a transmissive diffraction grating, disposed so that light is intercepted from the input port and encounters the transmissive dispersive element at least four times before reaching any of the output ports.

Abstract: A microstructure for steering light is provided that may be stepwise controlled to provide tilt positions in two dimensions. The arrangement is two-dimensional since a tilt axis may be defined as the axis along which the base is tilted to move from one of the two tilt positions to the other. At least one additional tilt position is provided that cannot be reached from either of those two tilt positions by tilting the micromirror assembly along the tilt axis. Instead, such an additional tilt position requires that there at least be a tilt component in a direction orthogonal to the tilt axis.

Abstract: A reflective lamellar diffraction grating is provided that is suitable for a variety of applications, including applications related to C-band telecommunication functions. The average efficiency of the diffraction grating in S- and P-polarization states exceeds 90% while simultaneously providing a PDL less than 0.2 dB over the entire wavelength range used for C-band telecommunication functions. The diffraction grating is thus suitable for incorporation into various telecommunication systems, including a wavelength router configured for routing signals having a plurality of spectral bands.

Abstract: An optical ring is provided for propagating optical signal pairs over wavelength connections between nodes. Each optical signal pair includes two signals at different wavelengths. At one or more of the nodes, one signal of the pair acts as a transmit signal and the other acts as a receive signal. If a failure is detected the optical signal pair is redirected over a protection path without changing the wavelengths of the transmit and receive signals. This may be achieved by reversing a propagation direction for each of the signals comprised by the redirected optical signal pair.

Abstract: An apparatus and method for routing optical signals between a pair of input ports and a pair of output ports is provided. An optical switching arrangement adapted to shift among at least two distinct optical configurations is provided for directing the optical signals. In the first configuration, the optical signal from the first (second) input port is directed to the first (second) output port. In the second configuration, the optical signal from the first input port is discarded and the optical signal from the second input port is directed to the first output port.

Abstract: A wavelength router that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input ports and said output ports, and a routing mechanism. The free-space optical train can include air-spaced elements or can be of generally monolithic construction. The optical train includes a dispersive element such as a diffraction grating, and is configured so that the light from the input port encounters the dispersive element twice before reaching any of the output ports. The routing mechanism includes one or more routing elements and cooperates with the other elements in the optical train to provide optical paths that couple desired subsets of the spectral bands to desired output ports. The routing elements are disposed to intercept the different spectral bands after they have been spatially separated by their first encounter with the dispersive element.

Abstract: A microstructure for steering light is provided. A pivot member is connected with a structural film and supports a base that includes a reflective coating. A fixed rotational actuator is connected with the structural film and is configured to rotate the base on the pivot member upon actuation. A movable hard stop is connected with the structural film. The movable hard stop is configured such that in each of a plurality of its positions, the base assumes one of a plurality of tilt positions upon actuation of the fixed rotational actuator.

Abstract: A method and optical routing apparatus for directing an optical signal are disclosed. The optical routing apparatus includes an input port configured to provide the optical signal along an incident path and a plurality of output ports configured to receive the optical signal. An optical switching arrangement including a rotatable mirror and a plurality of fixed mirrors is operated to route the optical signal from the input port to one of the output ports depending on the configuration of the optical switching arrangement.

Abstract: A method for fabricating a micromachined device with a fast release step is provided. A first undoped sacrificial layer is deposited on a structural layer. A doped sacrificial layer is deposited on the first undoped sacrificial layer. A second undoped sacrificial layer is deposited on the doped sacrificial layer to produce a layered structure. An etchant is then applied to the layered structure.

Abstract: A diffraction grating is fabricated by forming two sets of parallel trenches in a crystal surface, one set with a crystalline-independent etching technique and the other made with a chemically crystalline-dependent etchant. The intersection of the two sets of trenches removes material from the crystal surface to produce an etched crystal surface that can be coated with a reflective material to form the diffraction grating or can be used as a master for batch fabrication of diffraction gratings.

Abstract: A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles &thgr;b spaced along the substrate surface, with the blaze angles substantially differ from the Littrow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface.

Abstract: A microstructure for steering light is provided that may be stepwise controlled to provide tilt positions in two dimensions. The arrangement is two-dimensional since a tilt axis may be defined as the axis along which the base is tilted to move from one of the two tilt positions to the other. At least one additional tilt position is provided that cannot be reached from either of those two tilt positions by tilting the micromirror assembly along the tilt axis. Instead, such an additional tilt position requires that there at least be a tilt component in a direction orthogonal to the tilt axis.

Abstract: A microstructure for steering light is provided. A pivot member is connected with a structural film and supports a base that includes a reflective coating. A fixed rotational actuator is connected with the structural film and is configured to rotate the base on the pivot member upon actuation. A movable hard stop is connected with the structural film. The movable hard stop is configured such that in each of a plurality of its positions, the base assumes one of a plurality of tilt positions upon actuation of the fixed rotational actuator.

Abstract: A wavelength router that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input ports and said output ports, and a routing mechanism. The free-space optical train can include air-spaced elements or can be of generally monolithic construction. The optical train includes a dispersive element such as a diffraction grating, and is configured so that the light from the input port encounters the dispersive element twice before reaching any of the output ports. The routing mechanism includes one or more routing elements and cooperates with the other elements in the optical train to provide optical paths that couple desired subsets of the spectral bands to desired output ports. The routing elements are disposed to intercept the different spectral bands after they have been spatially separated by their first encounter with the dispersive element.

Abstract: Optical systems for routing light that reduce or eliminate polarization-dependent loss are provided. Such optical systems generally accommodate an optical element that has an intrinsic polarization-dependent loss and which is disposed to be encountered twice by the light being routed. In some instances, the optical element may be a dispersive element such as a diffraction grating or prism, but the invention has more general applicability. The optical system additionally includes both a reflective element and a wave plate assembly disposed to be encountered by the light between encounters with the dispersive element.