Mid-IR applications

        Mid-infrared (Mid-IR, 2-8µm) is an attractive spectral band since it is involved in many important technologies. Not only in scientific research fields but also many industrial and military purposes such as thermal imaging, chemical/bio molecules sensing, free space communications and infrared countermeasures.

Fig. 1.(a). Illustration of IR countermeasures of an aircraft. (b). Molecules foot-print spectrum

PPXX technique is one of the major ways of Mid-IR generation (2-5µm) and manipulation. Compared to other methodologies of Mid-IR generation, PPXX technique is a significantly cost-effective, wavelength tunable, and efficient way due to the efficient nonlinear processes in the periodically poled nonlinear materials (LN, LT…etc), which enables the direct wavelength conversion from conventional NIR or visible light source. For example, watt-level CW output (fig.2.a) in the mid-infrared region of 2.7–3.45μm was successfully demonstrated in MgO:PPLN based single resonant cavity by Markku Vainio et al [1]. Besides, DFG is also an attractive way to generate mid-IR laser since its simple configuration and no precise optical alignment is needed.  

Fig. 2. (a).Output power of the four mirrors OPO as the idler wavelength is 3130nm. (b). General configuration of the single resonant optical parametric cavity.

        As a leading company of PPXX technique, HC Photonics (HCP) provides variety of PP-chips and accessory which are widely utilized in mid-IR applications. With accurate temperature control and poled periods tuning, 2-5mm with continuous wavelength tuning is feasible on a monolithic PP-chip. Besides, we also provide PP-chips with extreme length up to 8cm, which realize ultra-low threshold of OPO and greatly reduce the power requirement of pumping source. Considering the delicate optical alignment, HCP also provide the industrial solution such as customized fiber pigtailed frequency converter for your special application.



1. Markku Vainio, Jari Peltola, Stefan Persijn, Frans J. M. Harren, and Lauri Halonen, "Singly resonant cw OPO with simple wavelength tuning," Opt. Express 16, 11141-11146 (2008)

2. Paul Belden, DaWun Chen, and Fabio Di Teodoro, "Watt-level, gigahertz-linewidth difference-frequency generation in PPLN pumped by an nanosecond-pulse fiber laser source," Opt. Lett. 40, 958-961 (2015)

3. Wekipedia, "Infrared".