Regarding to big black speckle and cell like stripes in the IR images of a IR observation system introduced by the assembly precision, environment, the nonuniformity correction method and etc. after correction of the images for nonuniformity, an adaptive algorithm of nonuniformity correction based on neural network is introduced in this paper. And a real-time video signal processing system based on DSP and programmable devices is described in this paper in detail. Experimented with the IR observation system, the algorithm is able to despeckle images adaptively and the real-time realized in the hardware system proposed in this paper.
This paper discusses a design of optical transfer system used in carbon-dioxide laser therapeutic machine. The design of this system is according to the requirement of the therapeutic machine. The therapeutic machine requires the movement of laser transfer system is similar to the movement of human beings arms, which possesses 7 rotating hinges. We use optical hinges, which is composed of 45 degree mirrors. Because the carbon-dioxide laser mode is not good, light beam diameter at focus and divergence angle dissemination are big, we use a collecting lens at the transfer system output part in order to make the light beam diameter at focus in 0.2 to approximately 0.3 mm. For whole system the focus off-axis error is less than 0.5 mm, the transfer power consumption is smaller than 10%. The system can move in three dimension space freely and satisfies the therapeutic machine requirement.
This paper studies the LiNbO3 crystal rohomboprism machining problem, introduces how to select material including initial separation and finish separation and determine optical axis, proposes a method to determine material uniformity according to graph of interference fringes and discussed the technology problems of rough lapping, finish lapping and polishing and some problems should be attended to e.g. temperature, spindle rotating speed, abrasives, hanging method and iris controlling and so on. Some methods for measuring rhomboprism and formula for calculating deviation angle are given. The workpiece machined by the machining technology proposed in this paper surface flatness is 0.1 micrometers , roughness is Ra 0.008 micrometers (P equals III), angle error is 1', parallelism error is 15', which can meet the drawing requirements.
This paper introduces the properties of BaF2 crystal material. According to these properties material selecting is discussed including initial separation and finish separation, e.g. checking crystal lithogenesis, intercalation, cloud, uniformity and stress and so on. Determine methods are given also. The BaF2 machining technology is studied. Comparing different cutting methods we select the cutting method with steel saw blade. For the soft and brittle properties of BaF2, we probe the rough lapping finish lapping and polishing and for different procedure give selecting principle for abrasive, spindle rotating speed, machining allowance, size tolerance, and iris and relative data. Through machining experiments we find that the workpieces machined adopting the technology proposed in this paper can meet the drawing requirement e.g. N equals 1, (Delta) N equals 0.1, center thickness d equals 4 +/- 0.10 surface roughness Ra 0.008 micrometers (P equals III). The paper also points out some problems should be attended to in machining BaF2 crystal.
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