Wavelength Conversion Module for Visible, Near-IR, and Mid-IR Light Generation
NEL produces periodically poled lithium niobate(PPLN) waveguide modules for visible, near-IR, and mid-IR light generation. The module consists of a PPLN waveguide, a thermoelectric cooler, and a thermistor. A custom design of the poling period is available. Please specify your pump and SHG/SFG/DFG wavelenghts down to 2 decimal places when ordering modules.
The quasi-phase matched PPLN waveguide modules provide a variety of wavelength conversion capability without using cavity structures.
Second harmonic generation(SHG), sum frequency generation(SFG), and diffrence frequency generation(DFG) are second-order nonlinear optical processes. The second order dipole polarization is induced by electric fields of input lights. In the phrase of quantum optics, a new photon is generated from input two photons. The interactions are expressed as follows;
SHG (for example 532 nm)
SFG (for example 578 nm)
DFG (for example 3 μm)
Quasi-phase matching is achieved by inverting the porlarization every half of the coherence length with respect to the light propagation direction.
For more information, please refer following references.
- A. Yariv and P. Yeh, Photonics: Optical Electronics in Modern Communications (Oxford University Press, 2007)
- M. Asobe et al., IEICE Trans. Electron. E88-C, 335 (2005)
The wavelength conversion is limited by the beam divergence in bulk PPLN crystals. However, in PPLN waveguide, the wavelength conversion is enhanced by the beam confiment effect throughout the waveguide length . The conversion efficiency of the PPLN waveguide is two order of magnitude larger than that of bulk PPLN crystal.
Typical conversion efficiency of PPLN waveguide is larger than 100%/W at visible region. Conversion efficiency η is defined as
Pk = η Pl Pm
where Pk is output power (k = 2ω at SHG, ωp at SFG, ωi at DFG) while Pl and Pm are input power (l = m = ω at SHG, l = ωs and m = ωi at SFG, l = ωp and m = ωs at DFG).
|4||Cooler (+)||8||Cooler (-)|
(1)SFG (578 nm)
|Required pump wavelengths||1030 nm 1319 nm|
|SFG wavelength||578 nm|
|Efficiency||> 100 %/W
When pump power is below 100 mW
|Operation temperature(Top)||Typ.: >30 degree C
Temperature fine tuning is required for satisfying the phase match condition
|TEC Current||2 A max|
|Module size||54 mm x 30 mm x 11.2 mm|
|Window||IR-cut filter or Visible-AR window|
|Input fiber※||980 nm PANDA fiber with FC / APC connector|
※WDM fiber coupler is not included.