.1.57 ¦¬m Intracavity Optical Parametric Oscillator

The 1.57μm laser, because of its eye-safe characteristic, high atmospheric transmission capacity and the availability of suitable detection devices, has enormous potentials in many applications such as communications, laser warning, laser radar and ranging, remote-sensing of aerosols. OPO as a kind of high coherence tunable laser source has been attracting many researches 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 II noncritically phase matched (x-cut, θ=90⁰, φ=0⁰) singly resonant KTP-OPO system, laser at 1.57μm can be achieved. An intracavity OPO with quasi-continue output at 1.57μm has been realized and the output laser properties under diode-end-pumping and diode-array-side-pumping have been researched. 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 analyzed. The fundamental principle of OPO construction is summarized.3 , An IPOPO is realized by placing a KTP crystal into a concave-concave cavity of a LD pumped, AO Q-switched Nd:YVO₄ laser and for the first time, the concave-concave cavity is used to lower the OPO's threshold. Through the discussion of the threshold formula of the singly resonant OPO, a concave-concave cavity and a short OPO cavity length are employed in the setup to decrease the OPO's pumping threshold. The parameters of output laser have been measured at different repetition rates of the AO Q-switch and at the output mirrors with different transmissions. The influences of...