Development of coherent tunable source in 2–16 𝜇m region using nonlinear frequency mixing processes

Pramana

Udit Chatterjee1¹ 

[1] Laser Laboratory, Physics Department, Burdwan University, Burdwan 713 104, India$$

关键词: Nonlinear frequency conversion;    infrared radiation;    nonlinear materials;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

A very convenient way to obtain widely tunable source of coherent radiation in the infrared region is through nonlinear frequency mixing processes like second harmonic generation (SHG), difference-frequency mixing (DFM) or optical parametric oscillation (OPO). Using commonly available Nd:YAG laser and its harmonic pumped dye laser radiation as parent beams, we have been able to generate coherent tunable infrared radiation (IR) in 2–16 𝜇m region using different nonlinear crystals by DFM and OPO. We have also generated such IR source in the 4–5 𝜇m region through SHG of CO2 laser in different infrared crystals. In the process we have characterized a large number of nonlinear crystals like different borate group of crystals, KTP, KTA, LiIO3, MgO:LiNbO3, GaSe, AgGaSe2, ZnGeP2, AgGa1−𝑥In𝑥Se2, HgGa2S4 etc. To improve the conversion efficiencies of such frequency conversion processes, we have developed some novel schemes, like multipass configuration (MC) and positive optical feedback (POF). The significance of the obtained results lies in the fact that to get the same conversion in SHG or DFM, one now requires fundamental input radiation with much lower intensity.

【 授权许可】

Unknown