The Research Of Mini-type Eye-safe Laser

1.5Xμm eye-safe wavelength lasers are just at the window of the atmosphere, have good smoke transmission and high object reflectivity and so on, have been proved to have paramount applications in the filed of laser rangefinder, laser radar, remote sensing and medicine, ect, is kind of ideal eye-safe wavelength region. Especially the 1.57μm lasers obtained by the technology of optical parametric oscillator are quite suitable for mini-type solid state lasers due to its compactness configuration, light weight, high reliability and other advantages.In this paper, from the notion of the eye-safe laser, various methods which can obtain 1.5Xμm laser were simple introduced, but put emphasis on optical parameter oscillator because of the mini-type problem, and went into particulars of OPOs'theory. And a mini-type, high efficiency, conductive cooling, Cr⁴⁺:YAG passive Q-swithed, Nd:YAG KTP-OPO 1570nm eye-safe laser was designed based on the theory. Some relevant experiments were also done to study the properties of the laser.The contents are as follows:1. Simply introducing the eye-safe laser, and the history, the development and the meaning of the OPO were illuminated in detail.2. The basic theory of the OPO was simply introduced, and from a three wave nonlinear process, the theories of the OPO were analyzed particularly. Based on this, the OPOs'phase matching, running method, running condition, the plus, the threshold, the conversion efficiency, the output characteristic and any other properties were studied.3. A special kind of prism resonator was designed because of the mini-type requirement, the theory of the resonator was also showed. The configuration of the mini-type eye-safe laser and its component, contains pump source, Q-switch, and cooling module, were also designed.4. Some relevant experiments were done to study the mini-type eye-safe laser, such as the influence of the Q-switch, the configuration of the resonator, the effect of the output mirrors'transmission rate.5. A whole mini-type eye-safe laser was assembled, it is 25mm×25mm×85mm in size, and on the test, the OPO laser average output energy is 15mJ/pulse, pulse width is about 3.8ns, laser angle of divergence is about 9mard, the conversion efficiency between electricity to optical is about 1.5‰, the ratio of output power to the whole volume is up to 2.966mJ Hz/cm³.