.1.57 ¦¬m Intracavity Opo Output Characteristics

The 1.06um laseis which are being broadly used in modem photoelectric devices tend to hurt people's eyes. In view of this, many scientists are trying work out novel laseis at eye-safe wavelengths. The lasers, whose output wavelength is near 1.57μrn are widely used in range-finding because of they ate relatively safe to people's eyes. Optical Parametric Oscillator (OPO) pumped by 1.06μm Nd:YAG laser outputs at 1.57um and is one of the most effective way to realize the eye-safe laser.OPO as a kind of high coherence tunable laser source has been attracting many researchers for its unique characters. Recently, with the development of nonlinear frequency conversion crystal (NFCC) and solid-state laser technology, research activities in this area are heating up. The research on KTP-OPO system lasing at 1.57μm eye-safe wavelength is one of the favorite topics. By using a type IInoncritically phase-matched (x-cut, θ= 90°, φ = 0°) singly resonant KTP-OPOsystem, laser at 1.57um can be achieved. In this thesis, an eye-safe 1.57μm KTP-OPO pumped by a Cr⁴⁺:YAG passively Q-switched Nd:YAG laser is theoretically and experimentally studied, the contents of dissertation can be outlined as follows:1. The fundamental theory and general research on OPO system are introduced. The applications of OPO system in many fields are discussed.2. By utilizing coupled wave equations of three-wave interaction process, the theory of OPO system is studied and some key parameters such as pump threshold and conversion efficiency are analyzed. The fundamental principle of OPO construction is summarized.3. By using Xenon flash pumped, Cr⁴⁺:YAG Q-switched Nd:YAG cavity as the pump source, an intracavity KTP-OPO (optical parametric oscillator) system lasing at I.57um wavelength is realized. The Q-switehing effect of Cr⁴⁺:YAG crystal is analyzed and under the condition that the OPO has the single-pulse output, the...