Abstract: A projecting optical system includes, in order from the side of a screen, a first lens unit of positive refractive power of retrofocus type and a second lens unit composed of one positive lens, wherein parameters of the projecting optical system are determined such that an off-axial principal ray crosses an optical axis between the first lens unit and the second lens unit, and the following condition is satisfied:0.2<D2f/f<0.95 (1)where D2f is a distance from a vertex of a lens surface facing the screen side of the second lens unit to an original-image display plane, and f is a focal length of the projecting optical system.

Abstract: A high-speed optical modulator module which includes: a lead frame having an outer lead frame and an inner lead frame, the outer lead frame for receiving a high-speed signal; a substrate, in which a metal base having a matching impedance device, and a submount having a laser diode thereon, are formed; a first multi-bonding wire for electrically connecting the inner lead frame of the lead frame to one end of the matching impedance device; a second multi-bonding wire for electrically connecting the other end of the matching impedance device to one end of the metal base; and a dual-bonding wire for electrically connecting the other end of the metal base to the laser diode. The matching impedance device includes a matching resistor and a compensation capacitor connected in parallel. The module is formed by packaging and sealing the components other than the outer lead frame.

Abstract: A light modulator for both intensity and phase modulating coherent light on a pixel-by-pixel basis includes a modulating material responsive to an electric potential for modulating the intensity of coherent light passing through the modulating material, and electrodes for applying an electric potential across the modulating material on a pixel-by-pixel basis. The coherent light associated with a first set of pixels has a different optical path length through the modulating material than does the coherent light associated with a second set of pixels. The modulating material is a liquid crystal material. The electrodes include a set of first reflective pixel electrodes embedded in the liquid crystal material, the first reflective pixel electrodes having a first thickness, and a set of second reflective pixel electrodes embedded in the liquid crystal material, the second reflective pixel electrodes having a second thickness.

Abstract: A passive acousto-optic modulator for the modulation of a light beam as a function of a variation in air pressure comprising a beam splitter arranged relative to the beam so as to produce a signal beam and reference beam, the beam splitter ideally comprising a flat interface located between two optically transparent mediums such as the end of an optic fiber located within air, the interface being arranged relative to the light modulator such that when the light beam travels through the interface, some of the light beam is able to pass through the interface to form the signal beam, the rest of the light beam being reflected back off the interface to form the reflected reference beam; a light modulator which modulates the signal beam, the light modulator comprising an approximately flat optically reflective surface capable of movement, the reflective surface being located in a position which, at rest is a predetermined distance from the beam splitter and is approximately parallel to and facing the beam splitter

Abstract: A level-setting attenuator for generating an output signal having a predetermined optical power from an input optical signal having a varying power is disclosed. The level-setting attenuator includes a telecentric imaging device, a variable atttenuator, an optical power detector and control electronics. The telecentric imaging device collimates a received optical signal which is received and partially attenuated by the variable attenuator. In some embodiments, the variable attenuator generates an attenuated signal portion and an unattenuated signal portion. The attenuated signal is directed, by the variable attenuator, to an optical power detector operable to measure the power of the attenuated optical signal. The detector sends a signal indicative of the measurement to control electronics. The control electronics are operable to generate a control signal for controlling the attenuation of the unattenuated signal portion so that is has the predetermined power level.

Abstract: An inventive method for the manufacture of an array of M.times.N thin film actuated mirrors for use in an optical projection system includes the steps of: providing an active matrix; depositing a thin film sacrificial layer; depositing a protective oxidation layer on top of the thin film sacrificial layer; creating an array of empty cavities; depositing an elastic layer; forming an array of conduits in the elastic layer; depositing a second thin film, a thin film electrodisplacive and a first thin film layers, successively, thereby forming a multiple layer structure; patterning the multiple layer structure, until the thin film sacrificial layer is exposed; and removing the thin film sacrificial layer to thereby form an array of M.times.N thin film actuated mirrors. The protective oxidation layer is deposited on top of the thin film sacrificial layer before the formation of each of the empty cavities, which, in turn, prevents phosphorus on the surface of thin film sacrificial layer from getting oxidized.

Abstract: A multiple quantum well spatial light modulator combines both optically addressed and electrically addressed portions on a single wafer. The electrically and optically addressed portions may be physically distinct or combined. To fabricate the modulator, a portion of an optically addressed multiple quantum well spatial light modulator is configured as an electrically addressed portion by pixellating that portion of the multiple quantum well wafer. The frequency of the applied voltage to the electrically addressed portion is increased such that the voltage switches faster than both the dark and illuminated screening time. The electrically and optically addressed portions may be combined or positioned side-by-side. The spatial light modulator has applications in a wide variety of low-cost, high performance pattern recognition systems. In one system, a first infrared beam impinges the electrically addressed portion of the modulator and picks up the pattern electrically written thereon (i.e., the template image).

Abstract: An integrated digital light modulator. In one embodiment, a light beam is split into a set of binary weighted beams which are then individually switched on or off by an optical switch. The weighted beams which are conveyed by the optical switches are then recombined to produce a modulated beam. In this manner, a fast inexpensive integrated digital light modulator may be advantageously obtained. Broadly speaking, the present invention contemplates a digital optical power modulator that comprises a binary power divider and an optical modulator. The binary power divider is configured to receive an input light beam and split it into a set of weighted beams. The optical powers of the weighted beams are related in that the ratio of the optical powers of any two weighted beams is substantially an integer power of two. The optical modulator receives the set of weighted beams from the binary power divider and receives a digital signal.