Abstract: An infrared emitting semiconductor device having a layer-shaped infrared emitting region with a superlattice structure. The superlattice structure consists of thin alternating narrow and wide wells separated by thin barriers. The narrow well has one quasibound state E'.sub.0 while the wide well has two states E.sub.0 anad E.sub.1 with E'.sub.0 being located between E.sub.0 and E.sub.1. Under proper bias, an electron in state E.sub.0 can resonately tunnel out of the well through the quasibound state E'.sub.0 to the first excited state E.sub.1 of the next wide well. This electron can then relax to the ground state E.sub.0 where it can resonately tunnel to the next wide well and repeat the process. Infrared radiation with its photon energy equal to E.sub.1 -E.sub.0 is emitted as the electrons relax from E.sub.1 to E.sub.0 in the wide wells.

Abstract: Sum frequency generating devices are disclosed. The devices include a waveguide having a multilayer structure comprising at least one nonlinear semiconductor material. In a preferred embodiment, each of the layers of the multilayer structure has the same thickness and alternate layers have a first and a second predetermined refractive index. The sum frequency output generated by two contra-propagating beams of fundamental wavelengths within the waveguide is enhanced by the multilayer structure of the waveguide. The sum frequency output is in a direction different from that of the waveguide and contrapropagating fundamental beams.

Abstract: The invention described is a process of and an apparatus for recognizing the size, location, orientation etc. of an object without human intervention. The convolution technique is used to solve the field theory equations to generate linearity signals characteristic of points in the optical image of the object. The linearity signal is perception of linear or strip-like features in an image. The recognition is achieved by analyzing the linearity signals.

Abstract: Photoconductors with channels that lie in the surface depleted region of a GaAs structure are described. These devices have nanoampere bias current, and exhibit photoconductive gain. In contrast to other photoconductors, their low frequency responsivity is of the same order as that in the GHz region, alleviating problems of equalization necessary in receiver applications. As well, these devices exhibit over 60 dB isolation as optoelectronic switches.

Abstract: This disclosure presents an alternative, improved approach to the RF only quadrupole mass spectrometers. The ions whose masses place them near the stability limit for a given operating voltage and RF frequency, can be strongly influenced by the application of a very small dc voltage to the quadrupole rods. If this voltage is modulated at a low frequency (typically a few hundred hertz), the (a,q) values will pass alternately through the stability boundary and ions will be transmitted with the imposed frequency. The advantages of the new approach are two-fold (a) lock-in amplifier synchronous detection schemes can be used. These give improved signal/noise ratios. Background noise due to photons, soft X-rays or excited neutrals--often a problem in quadrupole mass filters--will not be modulated and will not be detected. (b) Higher resolution can be achieved.