Projector optimized for modulator diffraction effects
An optical system that includes a micro-mirror array optical modulator that can selectively modulate an incident light beam having a defined narrow spectral bandwidth to encode data thereon based on commands to an ON-state or an OFF-state of a micro-mirror. The micro-mirror array optical modulator can redirect light by diffraction and reflection to provide an output modulated light beam that exhibits a diffraction handedness dependent described by an arrangement of diffraction orders that depend in part on the narrow spectral bandwidth of light incident thereupon. An optical element has an optimized limiting aperture for defining portions of a modulated light beam that are blocked and remaining portions that are transmitted. An ON-state efficiency and an OFF-state contrast of an optically transmitted modulated light beam can depend on the diffraction handedness of the output modulated light beam relative to a size and a shape of the optimized limiting aperture.
1. A method for characterizing performance of a first micro-mirror array optical modulator and a second micro-mirror array optical modulator of a light display system, the method comprising:
(a) detecting detail of diffraction orders of light, or measuring a light collection efficiency and a contrast, resulting from a first incident beam of light on the first micro-mirror array optical modulator that is modulating a spectral bandwidth of the first incident beam of light, as controlled in an ON-state condition and an OFF-state condition, with respect to an optical element that has an aperture having a size and a shape that transmits portions of the modulated beam of light and blocks remaining portions of the modulated beam of light;
(b) removing the first micro-mirror array optical modulator from use in the light display system and placing the second micro-mirror array optical modulator into use in the light display system;
(c) detecting the detail of diffraction orders of light, or measuring the light collection efficiency and the contrast, resulting from a second incident beam of light on the second micro-mirror array optical modulator that is modulating the second incident beam of light, as controlled in the ON-state condition and the OFF-state condition, with respect to the optical element; and
(d) classifying the first micro-mirror array optical modulator or the second micro-mirror array optical modulator based on the detected detail of diffraction orders of light or the measured light collection efficiency and contrast for each of the first micro-mirror array optical modulator and the second micro-mirror array optical modulator.
2. The method of claim 1 , wherein classifying the first micro-mirror array optical modulator or the second micro-mirror array optical modulator is based on diffraction handedness patterns measured for the first micro-mirror array optical modulator and the second micro-mirror array optical modulator.
3. The method of claim 1 , wherein the first incident beam of light and the second incident beam of light are from a laser source and associated with a single color.
4. The method of claim 1 , wherein the first incident beam of light and the second incident beam of light are from one of three primary light sources that are laser light sources in a laser projection system.
5. The method of claim 1 , wherein the first incident beam of light and the second incident beam of light are from one of six primary light sources that are laser light sources in a laser projection system.
6. The method of claim 1 , wherein each of the first micro-mirror array optical modulator and the second micro-mirror array optical modulator include a micro-mirror that is smaller than 20 wavelengths of the incident light beam.