Richard Turner

Electrically addressed spatial light modulator that uses a dynamic memory

The operating characteristics of a 64 x 64 array electrically addressed spatial light modulator that uses a dynamic memory on a very-large-scale-integration chip and a ferroelectric liquid-crystal modulator are discussed.

Policy Strategies, Teacher Salary Incentive, and Student Achievement: An Explanatory Model

As economies of scale increase, school districts, by means of policy strategy, trade class size against salary incentive for teachers. This idea is developed and related to district-level achievement through an explanatory, structural equation model. The model is tested on data on student achievement in 102 Colorado school districts. The results show that the model is moderately successful for explaining reading achievement in grades 5, 6, 11, and 12. However, factors not yet included in the model are believed to have strong effects.

Optical correlator using very-large-scale integrated circuit/ferroelectric-liquid-crystal electrically addressed spatial light modulators

The use of 2-kHz 64 × 64 very-large-scale integrated circuit/ferroelectric-liquid-crystal electrically addressed spatial light modulators as the input and filter planes of a VanderLugt-type optical correlator is discussed. Liquid-crystal layer thickness variations that are present in the devices are analyzed, and the effects on correlator performance are investigated through computer simulations. Experimental results from the very-large-scale-integrated/ferroelectric-liquid-crystal optical-correlator system are presented and are consistent with the level of performance predicted by the simulations.

CMOS photodetectors for correlation peak location

The design and operation of CMOS photodetectors for locating correlation peaks in an optical processor are discussed. The detectors, which are fabricated in silicon CMOS, employ analog position sensing and on-chip circuitry to sequentially find intensity peaks. Two test devices are described: a two element competitive array with 400 /spl mu/m/spl times/180 /spl mu/m 1-D sensors and a 400 /spl mu/m/spl times/400 /spl mu/m 2-D sensor. The 2-D sensor resolves beam displacements of 0.25 /spl mu/m and the two-element competitive array demonstrates combined circuit and photodetector response times down to 20 /spl mu/s.<<ETX>>

Applications of binary and analog hydrogenated amorphous silicon/ferroelectric liquid-crystal optically addressed spatial light modulators

Analytical and experimental results that show novelty filtering, optical phase conjugation, and real-time edge enhancement by using optically addressed spatial light modulators that comprise amorphous silicon photodiodes and analog and binary ferroelectric liquid-crystal modulators are presented. The advantages of these devices for the above applications include high-speed, low-power operation and high spatial resolution.

Optoelectronic hit/miss transform for screening cervical smear slides.

An optoelectronic morphological processor for detecting regions of interest (abnormal cells) on a cervical smear slide using the hit/miss transform is presented. Computer simulation of the algorithm tested on 184 Papsmear images provided 95% detection and 5% false alarm. An optoelectronic implementation of the hit /miss transform is presented, along with preliminary experimental results.