Abstract:
An optical membrane device (110) and method for making such a device (110) are described. This membrane is notable in that it comprises an optically curved surface (250). In some embodiments, this curved optical surface (250) is optically concave and coated, for example, with a highly reflecting (HR) coating to create a curved mirror. In other embodiments, the optical surface is optically convex and coated with, preferably, an antireflective (AR) coating to function as a refractive or diffractive lens.
Abstract:
An alignment structure (100) maintains an optical fiber in a bore(113). The structure is fixed on a bench and is passively or ac tively aligned with a light source. Then the structure may be welded or soldered to the optical bench whereby the alignment may suffer due to heat transfer. To correct this, the alignment structure can be plastically deformed to correct the alignment after thecomponents have been fixed. The alignment structure has a substantially constant cross section in a z-axis direction as well as flexible links in order to allow displacements orthogonal to the optical axis. This mouvements will be initiated by seizing the component with a micro-positioner at a handle (136) and displacing it over the elastic limit to achieve permanent deformation.
Abstract:
An integrated optical monitoring system comprises a hermetic package and an optical bench sealed within the package. An optical fiber pigtail enters the package via a feed-through to connectto and terminate above the bench. A tunable filter is connected to the top of the bench and filters an optical signal transmitted by the fiber pigtail. A detector, also connected to the bench, detects the filtered signal from the tunable filter. Thus, the entire system is integrated together, on a single bench within a preferably small package. This configuration makes the system useful as a subsystem, for example, in a larger system offering higher levels of functionality and optical signal processing capability.
Abstract:
A structure that is compatible with passive alignment, and is capable of integration onto a micro-optical bench system, provides for the secure attachment of optical components to the bench. The structure comprises a base and a clip structure for an optical component that is formed in the base. The clip structure can be etched into bulk material of the base. In one implementation, the clip structure is created using reactive ion etching in silicon or silicon-on-insulator (SOI) wafer material. In the preferred embodiment, the clip comprises an alignment wall and a resilient arm. The resilient arm engages a first side of the optical component to urge a second side of the optical component into engagement with the alignment wall. This cooperation between the arm and the alignment wall allows for precise registration of the optical component against the alignment wall to scales attainable with semiconductor lithography.
Abstract:
A tunable Fabry-Perot filter includes an optical cavity bounded by a stationary reflector and a deformable or movable membrane reflector. A second electrostatic cavity outside of the optical cavity includes a pair of electrodes, one of which is mechanically coupled to the movable membrane reflector. Voltage applied to the electrodes across the electrostatic cavity causes deflection of the membrane, thereby changing the length of the optical cavity and tuning the filter. The filter with the movable membrane can be formed by micro device photolithographic and fabrication processes from a semiconductor material in an integrated device structure. The membrane can include an inner movable membrane portion connected within an outer body portion by a pattern of tethers. The pattern can be such that straight or radial tethers connect the inner membrane with the outer body. Alternatively, a tether pattern with tethers arranged in a substantially spiral pattern can be used.
Abstract:
An optical probe for emitting and/or receiving light within a body comprises an optical fiber that transmits and/or receives an optical signal, a silicon optical bench including a fiber groove running longitudinally that holds an optical fiber termination of the optical fiber and a reflecting surface that optically couples an endface of the optical fiber termination to a lateral side of the optical bench. The fiber groove is fabricated using silicon anisotropic etching techniques. Some examples use a housing around the optical bench that is fabricated using LIGA or other electroforming technology. A method for forming lens structure is also described that comprises forming a refractive lens in a first layer of a composite wafer material, such as SOI (silicon on insulator) wafers and forming an optical port through a backside of the composite wafer material along an optical axis of the refractive lens.
Abstract:
A Raman system uses a semiconductor tunable laser subsystem to generate a tunable signal that is tuned over a scan band of greater than 50 nanometers. A probe system transmits the tunable signal to a sample. Finally, a detector system comprises a bandpass filter for filtering a Raman signal from the analyzed sample generated by the tunable signal, and a detector for detecting the filtered Raman signal.
Abstract:
Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.
Abstract:
A process for fabricating an optical membrane from polycrystalline silicon comprises first forming a sacrificial layer (110) on a handle wafer (100). Concavities (127) are etched into the sacrificial layer (110). Polycrystalline silicon membrane layer (125) is then formed on the sacrificial layer (110). The polycrystalline membrane layer (125) is subsequently polished to achieve the predetermined membrane thickness and surface smoothness, annealed, and then patterned. Finally, the sacrificial layer (110) is removed to release the membrane (125). The concavities (127) in the sacrificial layer (110) yield convexities in the polysilicon layer (125) to prevent stiction adhesion to the handle wafer (100). During processing, a mask used to pattern the membrane layer functions to protect a highly reflecting (HR) coating for the membrane.
Abstract:
An optical switch device includes a rolling shutter or membrane attached at one of its edges to a substrate near an optical port in the substrate. The rolling shutter can assume one of two states. In a first closed state, the membrane is uncoiled onto the substrate over the port such that light directed at the port impinges on the shutter. In a second open state, the membrane is rolled up away from the port such that light directed at the port impinges on the port. In one embodiment, a mirror is formed on the membrane such that when the membrane is in the closed state over the substrate, light directed at the port is reflected by the mirror. In one configuration, the optical port includes a hole or aperture such that light passed through the port without interference. The device can include a latch electrode the far end of the membrane such that when it is rolled out, it can be held in position by a latching voltage applied across the latch electrode and the substrate. Slits can be formed in the membrane to keep the mirror flat by relieving strain in the membrane and to allow gases in proximity to the device to pass through the membrane as it is activated. The shutter can include dimples to minimize the area of contact between the membrane and the substrate to reduce the probability of the two sticking together. The attachment edge of the membrane can be made shorter than its width to reduce distortions in the membrane to keep the mirror flat. A raised annular rim can be provided around the port such that when the shutter is held down over the port it is pulled taut and flat over the rim. This feature is also used to maintain flatness in the mirror. The switch device can be used as part of an array of optical switches.