A dual spectrum solar-blind ultraviolet (UV) corona detection system is designed in this paper. A common optical axis using a dichroic mirror is applied to this system in order to make visible light and ultraviolet light spectroscopy to ultraviolet detector and visible detectors. A high speed circuit of image processing based on TMS320DM642 DSP and a circuit that is used into system control and power management based on microcontroller are designed for the presented system. On the basis of the multi-threaded programming ideas, real-time image acquisition of ultraviolet and visible detectors, ultraviolet image noise reduction, image registration, dual spectral integration, Characteristic superimposing, serial communication and image display are achieved by using the DSP image processing circuit. Experimental results show that the dual spectrum solar-blind ultraviolet corona detection system has a good performance of corona detection based on ultraviolet and visible image fusion.
The design and imaging characteristic experiment of InGaAs shortwave infrared imaging system are introduced. Through the adoption of InGaAs focal plane array, the real time image process structure of InGaAs shortwave infrared imaging system is researched. The hardware circuit and image process software of the imaging system based on FPGA are researched. The InGaAs shortwave infrared imaging system is composed of shortwave infrared lens, InGaAs focal plane array, temperature controller module, power supply module, analog-to-digital converter module, digital-to-analog converter module, FPGA image processing module and optical-mechanical structure. The main lock frequency of InGaAs shortwave infrared imaging system is 30MHz. The output mode of the InGaAs shortwave infrared imaging system is PAL analog signal. The power dissipation of the imaging system is 2.6W. The real time signal process in InGaAs shortwave infrared imaging system includes non-uniformly correction algorithm, bad pixel replacement algorithm, and histogram equalization algorithm. Based on the InGaAs shortwave infrared imaging system, the imaging characteristic test of shortwave infrared is carried out for different targets in different conditions. In the foggy weather, the haze and fog penetration are tested. The InGaAs shortwave infrared imaging system could be used for observing humans, boats, architecture, and mountains in the haze and foggy weather. The configuration and performance of InGaAs shortwave infrared imaging system are respectively logical and steady. The research on the InGaAs shortwave infrared imaging system is worthwhile for improving the development of night vision technology.
Extension of Microchannel Plate (MCP) to a bulk conductive substrate was considered to be an effective approach to
eliminate ion feedback problem, and a vanadium iron lead phosphate glass had been identified can be tailored to have
appropriate volume conductivity and suitable for MCP fabrication. In this paper, a new reformulated vanadium iron lead
alumina phosphate glass was used to fabricate a bulk conductive glass MCP, the fabrication process is in the same way
as the conventional lead silicate glass MCP fabrication, but in the absence of a hydrogen firing treatment, although it was
succeed in fabricating some experimental samples of 25mm diameter full active area MCP with 10μm pore diameter and
40:1~60:1 length to diameter ratio, the experimental sample also demonstrated its bulk conductivity and certain
secondary electron emission property, but its gain is very low, especially its mechanical strength is insufficient. The
physical and chemical properties of this vanadium iron lead alumina phosphate glass, and the performance and behavior
of this glass during the bulk conductive glass MCP fabrication process, as well as its experimental sample test results
were detail described.
A fiber optic image inverter is a special type of fiber optic faceplate that rotate an image through a 180 degrees, and the
development of fiber optic image inverter is used to concentrated on the heat twisting process experiment based on an
existing glass system for production of fiber optic faceplate, but the conventional high expansion fiber optic faceplate
billets are hardly capable of withstanding a fast heat twisting operation without the billets broken which occurred during
the twisting operation, due to the thermal shock resistance property is defective in these conventional high expansion
fiber optic faceplate, so a long time heat twist operation cycle was normally adopted in most high expansion fiber optic
image inverter products manufacturers, caused a low yield efficiency and other shortages. In response, a program of
design and fabrication of fiber optic image inverters which originally initiated to develop a new high expansion fiber
optic glasses system with improved thermal shock resistance property, this program has yielded a new high numerical
aperture fiber optic glasses system which is capable of experience a fast heat twist operation process, and has been
demonstrated to produce a high numerical aperture fiber optic image inverter with a higher transmission property and
improved contrast transfer characteristic. In this paper we review the fundamental and design principle, fabrication
experiments process, and properties and performance of the fiber optic image inverters from a pilot run.
X-ray framing cameras (XFC) based on an ultra-high speed gated microchannel plate (MCP) as a routine diagnostic in
laser-driven Inertial Confinement Fusion (ICF) experiment have deployed on domestic facility for several years,
typically, these XFC devices used a normal MCP with 500μm thick and 12μm pore size, and achieved an optical
temporal gate leas than 100 picoseconds, but which are vulnerable to suffer a time broadened temporal response when
encounter heavy expose, due to the limited dynamic range of the normal MCP. We developed a 56mm format MCP with
250μm thickness and 6μm pore diameter, which objective is to promote the optical temporal gate and dynamic range for
the upgrade XFC, this MCP is fabricated by a special designed low resistance glass, the reduced thickness, small pore
size and increased gain linearity, offered which with ultra-fast temporal response and extended dynamic range characters.
In this paper, we review the mechanisms that limiting the temporal response and gain linearity of this ultra-high speed
gated MCP applied to XFC, and describe the design principle and development work of this ultra-fast temporal response,
extended dynamic range and larger format MCP, this MCP will assemble to the upgrade XFC which is designed by
CAEP and is currently in the final design stages.
The signal-to-noise ratio (SNR) and mean time to failure (MTTF) are two important attributes to describe the performance and operation life of an image intensifier. The presents of the ion barrier film (IBF) in Gen. III image intensifier, which used to suppress MCP's ion feedback, while dramatically improve the MTTF but significantly reduce the SNR, so more completely diminishing the ion poisoning source within the channels of MCP are crucial for improved Gen. III; image intensifier to thinned thickness IBF and achieving this two conflicting attributes promotion simultaneously. This research was originally initiated to develop a MCP with glass composition redesigned specially for GaAs photocathode image intensifier, proved which can be imposed an exceedingly intensive electron bombard degassing but without suffering a fatal gain degrade, and had achieved significantly improved SNR of Gen. III image intensifier but with a short distance to meet the lifetime success, so that our research work step forward to intent upon the restriction of ion poisoning source formation within the MCP substrate, we reformulated the MCP glass composition, and modified the microstructure of this MCP glass substrate though a glass-crystal phase transition during the MCP fabricate heating process, we present an innovative MCP based on a glass-ceramic substrate, with reformulated composition and close-linked network microstructure mix with many of nanometer size crystal grains, provide this MCP with sustainable high gain, lower ion feedback and less outgasing performance, this glass-ceramic MCPs are assembled to Gen. III image intensifiers which results showing promoting both the MTTF and SNR of Gen. III image intensifier.
To improve the Figure of Merit (FOM) and reduce the Equivalent Background Input (EBI) and
Fixed-Pattern-Noise (FPN) in image intensifier, NVT (North Night Vision Technology Co., Ltd) has
been researching and developing a low noise and high resolution Micro Channel Plate (MCP). The
density of dark current of this new MCP is less than 0.5PA/cm<sup>2</sup> (when MCP voltage at 1000V). The
FPN and scintillation noise are reduced remarkably. Channel diameter is 6 &mgr;m and open area ratio is
60&percent;∼70&percent;. The vacuum bakeout temperature could be as high as 500°C. This new kind of MCP will
be extensively used in the supper generation and the third generation image intensifiers.