Coherent mid-infrared (MIR) light has a plethora of important applications ranging from life-science to industrial processes. Simultaneous coverage of this region will enable the parallel detection of various chemicals and enhance the specificity of their detection . One of the most popular broadband infrared generation methods is nonlinear down-conversion from the near-infrared. An effective conversion can be achieved by using phase-matching and quasi-phase-matching in birefringent crystals and crystals with periodically poled structure respectively. Random quasi-phase-matching (RQPM) in poly-crystals is an alternative method that has recently shown great promise [2,3], which results in a gradual growth of the generated signal linear to the propagation length. Compared to generic phase-matching schemes, RQPM offers an unparalleled phase-matching bandwidth that is insensitive to incident angle. In addition, unlike single-crystals, poly-crystals can easily be grown into larger dimensions to enable longer interaction lengths.
© 2019 IEEEPDF Article