The figure schematically shows a micromachined Fabry-Perot interferometer that, when fully developed, would be part of a two-dimensional array of such interferometers in a flat-panel display device. The interferometers, arrays, and display devices according to this concept would be similar to those described in the preceding article, "Micromachined Interferometric Optoelectronic Display Devices" (NPO-19527). The basic principles of design and operation are the same, but there would be differences in some of the details.
The major difference in design would be that a device of this type would contain only one micromachined Fabry-Perot interferometer per pixel instead of three as in the devices of the preceding article. The major difference in operation is that instead of using each micromachined Fabry-Perot interferometer as an on/off modulator for light of a preset wavelength, one would use each such interferometer as a tunable band-pass filter and "off" switch: the voltage applied to the electrostatic-deflection electrodes of the interferometer in each pixel could be varied as a function of time to make light of a chosen wavelength pass through at a given time, or the voltage could be increased to a level sufficient to draw the interferometer mirrors together so that no light would pass through. That is, by controlling the voltage applied to each pixel, one could either make it appear to glow in a chosen color or else go dark.
The feasibility of this concept was demonstrated in an experiment on a prototype. The distance between the mirrors was varied, causing the transmitted color to vary between red and blue.
This work was done by Tony K. T. Tang, Linda M. Miller, and Judith A. Podosek of Caltech for NASA's Jet Propulsion Laboratory. NPO-19528
This Brief includes a Technical Support Package (TSP).
Variable-wavelength micromachined Fabry-Perot interferometers
(reference NPO19528) is currently available for download from the TSP library.
Don't have an account?
Overview
The document presents a technical support package from NASA's Jet Propulsion Laboratory (JPL) detailing the development of variable-wavelength micromachined Fabry-Perot interferometers. This technology aims to address the limitations of current display technologies, such as liquid crystal displays (LCDs) and gas plasma displays, which face challenges related to performance, scalability, and cost.
The core innovation involves a tunable single resonant optical interference filter that can selectively transmit light at specific wavelengths in the visible spectrum. The device consists of two parallel, flat transparent plates coated with reflective films, forming an optical cavity. By applying voltage to electrostatic-deflection electrodes, the distance between the plates can be adjusted, allowing for the tuning of the resonant wavelength. This mechanism enables the display to produce a narrow spectral band of colors, which can be varied dynamically, providing high-definition color output.
The document highlights the advantages of this new technology, including its ease of manufacturing through micromachining, improved performance, reduced costs, lightweight design, and low power consumption. These features make it suitable for a wide range of applications, including flat-panel displays, portable computer screens, high-definition televisions, and cockpit displays.
The feasibility of the concept has been demonstrated through experiments on prototypes, where the distance between the mirrors was varied to change the transmitted color from red to blue. This capability allows for each pixel in a display to function as a tunable band-pass filter, enabling precise control over the color output.
The document also notes that the design differs from previous models by utilizing only one interferometer per pixel instead of multiple, simplifying the structure while maintaining functionality. This innovation is positioned as a significant advancement in display technology, particularly for future high-definition television (HDTV) systems.
In summary, the document outlines a promising development in display technology that leverages micromachined Fabry-Perot interferometers to create high-definition, tunable color displays, addressing the need for scalable, cost-effective solutions in modern visual technology.
