808nm high power diode lasers, which is rapidly maturing technology technically and commercially since the
introduction in 1999 of complete kilowatt-scale diode laser systems, have important applications in the fields of industry
and pumping solid-state lasers (DPSSL). High power and high power conversion efficiency are extremely important in
diode lasers, and they could lead to new applications where space, weight and electrical power are critical. High
efficiency devices generate less waste heat, which means less strain on the cooling system and more tolerance to thermal
conductivity variation, a lower junction temperature and longer lifetimes. Diode lasers with Al-free materials have
superior power conversion efficiency compared with conventional AlGaAs/GaAs devices because of their lower
differential series resistance and higher thermal conductivity. 808nm GaAsP/GaInP broad-waveguide emitting diode
laser bars with 1mm cavity length have been fabricated. The peak power can reach to 100.9W at 106.5A at quasicontinuous
wave operation (200μs, 1000Hz). The maximum power conversion efficiency is 57.38%. Based on these high
power laser bars, we fabricate a 1x3 arrays, the maximum power is 64.3W in continuous wave mode when the current is
25.0A. And the threshold current is 5.9A, the slope efficiency is 3.37 W/A.
High power laser diode array with an emission wavelength of 1064nm is presented. The epitaxial structure is an
InGaAs/GaAsP strained-compensated single-quantum well structure. The modules CW output power can reach to 56.5W
at current of 80A. Because the heat capacity of st rather shorter pulse duration and lower duty cycle, the average driving
power in the laser chip is quite low, so the heating effect cemiconductor laser is very small, using pulse injection can
reduce temperature rising significantly. Aould be neglected. The definite relation between lasing wavelength and chip
temperature is developed. The temperature drift coefficient is 0. 45nm/ K
The paper introduces the overall structure and operating principle of a laser target identification system. Multi-sensor data fusion and information redundancy technology are adopted to achieve target characters synthetically judgment, which fits pratical engineering applications. In order to improving identifying distance of the targets and satisfy the miniaturization request of the system, heighten sensitivity and SNR (signal-to-noise ratio) of the sensor is a key technique. The paper discusses the technique. In addition, the paper has a detailed discussion on the overall structure of the system, target characteristic identification means and multi-sensor data fusion technology.
This paper describe a kind of measure instrument and its mechanism and composing that apply laser collimation technique and photoelectric detect technique to measure the linear error of cannon barrel, it can instead of the traditional optics measure method, and realize the scathe less automatic measure.
This paper describe the principle of a system that use the laser collimation system and coder to measure the parallelism of long-range multi-barrel rocket launcher. This measuring technology and this system can measure the variety multi-barrel’s parallelism that with diameter of between Φ100mm~Φ350mm and length under 10m, its measuring error σ≤10”.
The paper discusses the fundamental constitution of the later-atmosphere communication, which uses the semiconductor lasers as light sources and the photoelectric sensors as receiving devices. It makes a deep going study to the key technique -- that the problem of receiving the large-scale signals. To resolve this problem, the system uses plane mirrors, and hollow awls as the optical receiving aerial, at the same time; it makes an extensive-area photoelectric sensor whose diameter is 50 mm with 150 multiple photodiodes. The article also discusses and analyzes the technical difficulties in detail, which come from the extensive-area photoelectric receiving. The anti-light saturation of the extenive-area photoelectric sensors, the interference of background luminance and the problem of answering time. The system is successfully used in the practical engineering fields.
This paper study on a new scanning mini MTF automatic measure instrument and introduce the method of scanning the imagination point by grating and Fourier transformation to get the MTF, and designed a kind of MTF automatic measure instrument that could test the lens with caliber Φ<90mm, 28mm≤f≤250mm. This automatic measure instrument used CCD camera as the photoelectric detector, then use computer and its mightiness memory and processing function to realize auto test. This instrument is small and have high accuracy.
In the paper, a model of integrating sphere, which acts as a low- light-level source, is constructed on the basis of researching of the theory of integrating sphere and the method of Monte Carlo. The uniform distribution of photons is simulated by a large number of random numbers and the distribution of photons in the integrating sphere is molded. The method is practical to guide the design of integrating sphere. At last, the measurements to improve precise are discussed simultaneous.