An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.

Interferometric modulation of radiation

Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal. The elements are made by forming a sandwich of two layers and a sacrificial layer between them, the sacrificial layer having a thickness related to the final cavity dimension, and using chemical (e.g., water) or a plasma based etch process to remove the sacrificial layer.

Visible spectrum modulator arrays

The invention provides an optical coupling switch and flat panel display including an array of such optical coupling switches. The optical coupling switch includes a light storage plate adapted to set up conditions for total internal reflection such that light injected into the plate is internally reflected. A light tap is disposed proximal to a coupling surface of the light storage plate for coupling internally reflected light out of the light storage plate and into the light tap when the light tap is brought into contact with the light storage plate coupling surface. The light tap is capable of movement in a direction perpendicular to the light storage plate in response to an applied electrostatic force. The optical coupling switch includes a scattering mechanism, such as a scattering surface or scattering medium, for scattering light in the light tap into a viewing volume. With this configuration, the optical coupling switch provides an elegantly uncomplicated geometry that accommodates a range of actuation schemes for efficiently producing high-speed optical switching. Also provided is an optical display in which an array of light taps are disposed proximal to a light storage plate coupling surface. Each light tap is adapted to move in response to an applied electrostatic force in a direction perpendicular to the coupling surface, and each light tap includes a scattering surface for scattering coupled light. A light source is disposed at an edge of the light storage plate for injecting light into the plate. Control circuitry is provided connected to the array of light taps for applying an electrostatic force to selected one or more of the light taps in the array.

Micromechanical optical switch and flat panel display

Method for optical energy transfer and energy guidance uses an electric field (34) to control energy propagation (44) using a class of poled structures (39) in solid material (25). The poled structures, which may form gratings in thin film or bulk configurations, may be combined with waveguide structures. Electric fields are applied to the poled structures to control routing of optical energy. Techniques include frequency-selective switchable- and adjustable-tunable reflection, splitting, directional coupling, frequency-tunable switching and efficient beam combining, as well as polarized beam combining. Adjustable tunability is obtained by a poled structure which produces a spatial gradient in a variable index of refraction along an axis in the presence of a variable electric field. In one embodiment, the present invention is a method of switching a grating (48) which consists of a poled material with an alternating domain structure of specific period. When an electric field is applied across the periodic structure, a Bragg grating is formed by the electro-optic effect, reflecting optical radiation with a certain bandwidth around a center wavelength.

Method for manipulating optical energy using poled structure

An optical device includes a non-transparent substrate. The optical device further includes a first optical layer which is at least partially transmissive and at least partially reflective to incident light. The optical device further includes a second optical layer which is at least partially reflective to incident light. The second optical layer is spaced from the first optical layer. At least one of the first optical layer and the second optical layer is movable between a first position with a first distance between the first and second optical layers and a second position with a second distance between the first and second optical layers. Movement of the at least one of the first optical layer and the second optical layer between the first and second positions modulates the reflectivity of the device.

Photonic mems and structures

In an optical micromechanical method for changing the phase of guided waves and a measurement method for measuring very small mechanical displacements and/or mechanical forces or pressures, including the pressure of sound waves and ultrasonic waves, and/or accelerations, the distance d between a section (1') of an optical waveguide (1) in an integrated optic or fibre optic circuit and a phase-shifting element (5) separated from said section (1') by a gap (4) is varied by forces (6) or by thermal expansion due to changes in temperature. The phase of the guided wave (3) is thereby modulated, and reciprocally the changes in distance d and hence small mechanical displacements and the forces (6) which produce them are determined from the measured phase changes.

Optical modulation apparatus and measurement method

In an optical micromechanical process for changing the phase of guided waves for the purpose of modulating phase or intensity, and/or for switching guided optical waves between various outlets, and/or for deflecting optical waves, and/or for changing the resonance frequencies of frequency filters and resonators, and a measurement process for measuring very small mechanical displacements and/or mechanical forces or pressures, including the pressure of sound waves and ultrasonic waves, and/or accelerations, the distance d between a section (1') of an optical wave guide (1) in an integrated optic or fibre optic circuit and a phase-shifting element (5) separated from said section (1') by an intermediate space (4) is varied by forces (6) or by thermal expansion due to changes in temperature. The phase of the guided wave (3) is thereby modulated, and reciprocally the changes in the distance d and hence small mechanical displacements and the forces (6) which produce them are determined from the measured phase changes.

Walter Lukosz

Papers

Optical modulation apparatus and measurement method

Optical modulation and measurement process.