The parallel emission of the infrared light band of green laser pointer

The parallel emission of the infrared light band of green laser pointer can not be kept.
Diode laser frequency adjustment corresponds to a single gas absorption line. Laser spectral width corresponding adjustment to the single than the measured gas absorption line spectrum width narrower. By changing the current of the diode lasers, including the single absorption line of the laser wavelength is scanned emitted (see Figure A). During the launch of the laser scanning as a feature of the wavelength, the receiving unit to detect the light intensity will change and this change is only from the optical channel between the laser and the receiver under test gas molecules on the absorption of light. To detect single absorption line shape and size (see Figure A), used to calculate the gas content between the transmitter and receiver. The absorption lines of other gases does not appear in the selected wavelength range. The infrared light band can form a larger spot around the green light of green laser pointer .When every shift of green laser pointer begins
It occupies a unique position in the supersonic and hypersonic flow field studies, has become an effective diagnostic tool to study the combustion and flow. The laser gun diagnostic techniques. Laser Doppler velocimetry. Laser Doppler velocimetry (Laser Doppler volemeter-LDV) technology was developed in the mid-1960s. The basic principle is based on laser Doppler effect, the use of moving particles scattered light frequency shift to measure the speed, because the frequency shift of the scattered light contains the information of the particle velocity. Laser Doppler velocimetry of the process consists of the movement relationship between the three stationary particle of light, movement and stationary optical detector. The high spatial resolution of the LDV technique can measure the flow rate within a very small volume.
Often in aircraft engine design developed by many of the traditional methods can not solve test problems, the development of laser diagnostic techniques for aero-engine design and fault diagnosis has brought great convenience, a good solution to these problems. The temperature field measurement techniques. The traditional methods of measuring temperature is the point most of the measurements, there are many limitations, such as temperature measurement: the degree can not be too high, contact measurement: the destruction of the flow field, unable to obtain information for the entire temperature field.