Abstract: A new adaptive optics system and method of operation, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation:G'=(I-X(X.sup.T X).sup.-1 X.sup.

Abstract: A compact lightweight display system which can be used as a collimating eyepiece is provided. The system utilizes a cholesteric liquid crystal device in combination with an optical doublet. A partially reflective coating is at the interface between the two singlets which comprise the doublet. The design of this system reduces the number of element to air and/or element to element interfaces, thus reducing losses and ghosting while making a sturdier, more vibration tolerant display system.

Abstract: An abrasive material is proposed which is useful for the precision treatment of surfaces. This material may be in the form of an abrasive layer adhered by chemical and/or physical bonds to a carrier, the latter preferably made of a flexible material such as plastic. Alternatively, the abrasive material may be in the form of a free abrasive without a carrier. The abrasive material may be in the form of a vacuum condensate consisting of at last 80 atomic percent of an ultradispersed composite superhard diamond-like substance, preferably containing carbon, and including not more than 0.1 atomic percent hydrogen and oxygen, combined. The abrasive material is preferably obtained from the pulse-flows of an accelerated electroerosive plasma.

Abstract: A method and apparatus to detect fluorescence from a sample is provided. The optical system allows the user to continuously tune the wavelengths and bandwidths of the excitation source and the emission detection system. A peaking function automatically peaks the detected fluorescent signal by fine tuning the excitation and emission detection systems. A look-up table allows the fluorescent signal for a specific wavelength to be corrected for the wavelength dependence of the optical train. In one embodiment of the system the sample is simultaneously irradiated in more than one wavelength band, each wavelength band being independently tunable.