Considerable time for alignment is typically spent in the assembly of fiber optic components and subsystems. Presented here is a process that allows for pick-and-place assembly and automated alignment of these components. Fibers that are normally pre-attached to collimating or coupling lenses are left free in this process. The fiber position can then be re-located at the point of optimum performance by actively monitoring system performance. The fiber alignment can compensate for misalignment of the primary assembly components. Once the optimum fiber position is achieved the fiber is fused to the collimating or coupling lens element to provide the best mechanical and thermal stability of the finished assembly.
The Digital Micromirror Device (DMDTM) developed by Texas Instruments is a highly useful Micro-Opto-Electro-Mechanical Structures (MOEMS) device that enables high quality projection display. Acting as a semiconductor light switch, the DMD can modulate incident light to produce truly digital projection display systems. Illumination and projection optics are described for three fundamental display system architectures based on the DMD light modulator. These systems include one, two, and three DMD configurations all producing full color image projection. The single device configuration implemented with a rotating color filter system represents the least system hardware while providing the capability of full color and a high brightness monochromatic mode. A two device configuration using a rotating color filter combined with a secondary color splitting filter is of particular interest when using a light source that is spectrally imbalanced. The two device configuration is also capable of a high brightness monochromatic mode of operation. The three device configuration is the most efficient with respect to light throughput considerations providing the highest brightness full color projection with the DMD light modulators. Comparisons of system performance characteristics are described indicating the features of each configuration.
Although the action of a spatial light modulator (SLM) is usually restricted to certain locations on the operating curve of the complex plane, NASA is planning to use architectures that allow two continuously variable SLMs to function jointly so as to access the full interior of a closed curve in the complex plane. This paper describes three fundamental methods for attaining full complex modulation. The mathematics for two of these methods is presented, and signal decomposition in their terms is outlined.
A new technique for implementing fully complex spatial filters with a phase mostly deformable mirror device (DMD) light modulator is described. The technique combines two or more phase-modulating flexure-beam mirror elements into a single macro-pixel. By manipulating the relative phases of the individual sub-pixels within the macro-pixel, the amplitude and the phase can be independently set for this filtering element. The combination of DMD sub-pixels into a macro-pixel is accomplished by adjusting the optical system resolution, thereby trading off system space bandwidth product for increased filtering flexibility. Volume in the larger dimensioned space, space bandwidth-complex axes count, is conserved. Experimental results are presented mapping out the coupled amplitude and phase characteristics of the individual flexure-beam DMD elements and demonstrating the independent control of amplitude and phase in a combined macro-pixel. This technique is generally applicable for implementation with any type of phase modulating light modulator.
Two novel deformable mirror structures have been developed for spatial light modulators: an 'AM torsion beam' and a 'phase-mostly single-quadrant cantilever' beam. Both devices are well-suited to optical correlator input and filtering functions. Which the optical modulation characteristic of the torsion-beam modulator is essential amplitude only, which is well suited for use as the input modulator of the optical correlator, the characteristic of the one-quadrant modulator is a phase-mostly modulation whose amplitude changes are coupled to the phase changes; this renders it operable in the Fourier plane of the optical correlator as the filtering device.
Conference Committee Involvement (2)
Projection Displays XI
26 January 2005 | San Jose, California, United States
Projection Displays X
21 January 2004 | San Jose, California, United States