Abstract: An electrostatic actuator with inter-digital rotor and stator fingers formed in a the insulating and conductive layers of a wafer. The actuator is used to drive MicroElectroMechanical (MEMS) components, specifically micro-optical components such as mirrors, attenuators, switches, and tunable filters.

Abstract: In an optical amplifier, a filter is employed to reflect pump power into an erbium optical fiber carrying an input radiation signal, causing the signal to be amplified. The filter passes the amplified radiation signal to a partially reflecting optical interface which passes a small portion of the amplified radiation signal for monitoring purposes. Most of the amplified radiation signal is reflected by the interface and reflected again by another interface towards an output channel preferably parallel to the input channel for a compact design. Isolators may be employed between the filter and a first partially reflecting interface.

Abstract: The optical switch includes input optical fibers, output optical fibers, a lens, a movable mirror, and an actuator operative to move the mirror. Depending on a voltage applied to the actuator, the actuator selectively set the mirror to a first position corresponding to a first combination of optical paths, through which the light beam travels from the first set of the input optical fibers to the second set of the output optical fibers; and to a second position corresponding to a second combination of optical paths, through which the light beam travels from the first set to the second set. The first combination is different from the second combination, and a number of optical fibers of the first set and the second set is more than two.

Abstract: An optical circulator for transmitting light along a first optical path from a first optical port to a second optical port and along a second optical path from the second optical port to a third optical port, an optical interface in the first and second optical paths that passes the first beam but deflects the second beam to a highly reflective surface, wherein the plane of the highly reflective surface is at an angle to the optical interface such that the second beam is deflected from the highly reflective surface to the third port, and wherein the first port and the third port can be configured to utilize the same GRIN lens.

Abstract: A variable attenuator employs a shutter element that is inserted into the path of a beam of radiation. The shutter element comprises a transparent substrate with an opaque layer formed on top of the substrate. The opaque layer forms a pattern in the shape of dots on one part of the substrate and in the shape of a solid layer with holes therein on another part of the substrate. The pattern of holes and dots are such that the radiation transmission function of the element varies as a smooth linear function with the length of the shutter element. Therefore, by inserting the shutter element in a direction along its length into the path of the radiation beam, the amount of attenuation of the beam can be accurately controlled.

Abstract: In an optical amplifier, a filter is employed to reflect pump power into an erbium optical fiber carrying an input radiation signal, causing the signal to be amplified. The filter passes the amplified radiation signal to a partially reflecting optical interface which passes a small portion of the amplified radiation signal for monitoring purposes. Most of the amplified radiation signal is reflected by the interface and reflected again by another interface towards an output channel preferably parallel to the input channel for a compact design. Isolators may be employed between the filter and a first partially reflecting interface.

Abstract: A distributed matrix switch comprises a number of collimators each comprising a ferrule and a GRIN lens. A partially reflective coating is provided at the GRIN lens surface to pass a portion of an incoming light beam and to reflect the remainder. If the reflected portion is conveyed by means of an optical path to another collimators of similar construction, selected percentages of an incoming beam may be distributed along two or more optical paths. A receiving channel is then moved to different positions for receiving the portion of the light that is passed by one of the collimators to accomplish switching.

Abstract: The optical thickness of an optical device such as an interference filter or optical isolator is altered by applying stress thereto. This changes the frequency or isolation characteristics of the filter or isolator. The two sides of the device may be clamped to a member having a temperature expansion coefficient which is different from that of the device in order to apply tension or compression to the device in response to temperature changes. In this manner, the shifts in optical characteristics of the device due to temperature change is at least partially cancelled by the shifts in optical characteristics induced by stress applied by the member.

Abstract: At least one filter may be employed between two input channels and two output channels to selectively switch wavelengths of radiation between the input and output channels. In one configuration, a switch member having two different filters thereon is moved between two positions. In the first position, all of the wavelengths carried by a first input channel are reflected or transmitted through a first filter at the switch member to one of two output channels, and radiation of an additional wavelength is conveyed from a second input channel to the remaining output channel.

Abstract: A non-phase separable glass material for fabricating a GRIN lens comprises 5-20 mole % boron oxide and ratio R of network modifiers in mole % to the network former boron oxide in mole % is in the range of about 1-1.5. The melted preform of such glass material is extruded through an opening to form a glass rod where the extrusion process eliminates bubbles that may be present in the preform. Neodymium oxide may be added in the frit material for forming the preform to reduce friction forces in the extrusion process and reduces the stress in the glass rod. Centerless grinding may be performed to control the diameter and roughness of the surface of the rod to control the diffusion parameters during the subsequent ion-exchange.

Abstract: A non-phase separable glass material for fabricating a GRIN lens comprises 5-20 mole % boron oxide and ratio R of network modifiers in mole % to the network former boron oxide in mole % is in the range of about 1-1.5. The melted preform of such glass material is extruded through an opening to form a glass rod where the extrusion process eliminates bubbles that may be present in the preform. Neodymium oxide may be added in the frit material for forming the preform to reduce friction forces in the extrusion process and reduces the stress in the glass rod. Centerless grinding may be performed to control the diameter and roughness of the surface of the rod to control the diffusion parameters during the subsequent ion-exchange.

Abstract: GRIN lenses are made by an ion/exchange process. In order to make a GRIN lens whose gradient index varies slowly radially, a cylindrical glass rod of a sufficiently large diameter is immersed in a salty bath. The size of the lens may be reduced by grinding, polishing or chemically etching away a peripheral optically dispensable portion of the lens away from the axis of the lens so that the outer diameter of the lens is as small as 0.8 millimeters. When such a smaller lens is used in optical components such as circulators, switches, WDM's and isolators, such optical devices would also be reduced in size to fit within a limited space.

Abstract: An input light beam is deflected by a totally reflective surface of a corner prism towards another surface of the prism which is coated by a partially reflective coating. A predetermined percentage of the input power is reflected by this coating and the remainder transmitted therethrough. The reflected optical power is collected by an output fiber and the transmitted power is directed towards another coating which either totally or partially reflects such power to another output fiber to accomplish optical coupling.

Abstract: In order to tune the frequencies of radiation sources, a frequency locker is provided having equally spaced periodic frequencies with a spectral range substantially equal to the frequency spacing of a plurality of radiation sources with equally spaced apart frequencies. The periodic frequencies of the locker are slightly offset from those of the radiation sources. Radiation from each of the sources is passed through the locker and the radiation passed by the locker is detected and used to adjust the frequencies of the sources in order to tune the sources. The frequency locker includes an etalon with dimensions accurate to 0.5 microns or better. The dimension of the etalon may be controlled by controlling the thickness of spacers for maintaining vacuum or air gaps where the dimensions may be altered by thin film deposition and etching techniques. The optical path length of the etalon may also be changed by altering the angle of incidence of an incoming beam with the reflective surfaces of the etalon.

Abstract: The characteristic pass and rejection bands of an interference filter may be altered by changing the angle of incidence of light upon the filter. If the input beam is first collimated by a GRIN lens before it is transmitted to the interference filter, the characteristic wavelength bands of the filter can be altered by altering the distance of the input beam from the axis of the GRIN lens. Therefore, ferrules having imbedded therein input/output optical fibers may be provided to vary the distance of the input and output optical paths from the axis of the GRIN lens so that the desired spectral components in these paths are rejected or passed by the filter for performing multiplexing and demultiplexing.

Abstract: An optical coupler is formed by a GRIN lens having an axis and an optical medium contiguous to the GRIN lens but having an index of refraction that is different from that of the lens. An input optical fiber carries an input optical signal along a path substantially parallel to the axis of the lens but is offset from its axis. The lens collimates the input optical signal into a beam that impinges on the interface between the lens and the optical medium at a small angle. Fresnel reflection of the collimated beam at such interface is focused by lens to an output optical path also substantially parallel to the axis of the lens but at the same offset to the axis from the input optical path. The tapping percentage can be controlled by choosing an optical medium having the desired index of refraction. Additional interfaces can be formed between the optical medium and additional media, such as a thin glass disk for additional Fresnel reflections that are also coupled to the same output fiber.

Abstract: A tunable filter includes a filter whose characteristic wavelength band changes with the angle of incidence of the incoming light beam with respect to its normal direction, a motor for rotating the filter in order to change the angle of incidence, and a controller controlling the motor to rotate the filter by an amount so that the filter has a desired characteristic wavelength band. A variable attenuator for adjusting insertion loss between an input light beam and an output light beam includes a pair of input and output collimators, a cam connected to at least one of the two collimators, and a motor for rotating the cam for displacing one collimator relative to the other in order to adjust the insertion loss between the input and output light beams.

Abstract: A demultiplexer employs collimators for directing light of different wavelengths towards a filter so that light of one wavelength may be passed while reflecting light of other wavelengths. Light of the wavelengths that are passed or reflected may again be directed towards the same or different filter for further demultiplexing. The filter used has a characteristic wavelength band that varies with the angle of incidence to the filter. The same types of filter may be used for multiplexing. An input beam is passed through a filter at an angle of incidence at which light of a different wavelength would be reflected. Thus two input beams carrying such two wavelengths are directed towards the same location of the filter on opposite sides of the filter so that the reflected light of one wavelength will emerge as one beam with light of the other wavelength that passes through the filter. The emerging beam is then collected to multiplex light of the two wavelengths.

Abstract: This adhesive for laminating vinyl face stock to solid substrates has good initial peel strength, retains peel strength and is emulsion polymerized and compounded in the absence of sodium or lithium cations.

Abstract: The method of this invention makes multi-ply wood composite laminates from several wood veneer sheets using a 100% solids single component adhesive mixture, prepared in the absence of water, of isocyanate terminated prepolymer, polymeric diisocyanate and polysiloxane or aliphatic cyclosaturated C.sub.14 -C.sub.30 hydrocarbon.