Frequently Asked Questions
Our PPLN calculator can help you choose the best PPLN crystal for your application. For further details or advice our expert team is ready to help - we look forward to hearing from you.
Which PPLN crystal do I need?
Your PPLN crystal should be chosen to best match the operating conditions of your system. The most important factors to consider are the nonlinear process (SHG, OPO, etc.), the interacting wavelengths, and the crystal operating temperature, as these will define the required grating period. Similarly, the grating length is determined by the spectral bandwidth and temporal walk-off of the interacting wavelengths, particularly in short pulse systems.
To help you choose the best crystal for your system, a PPLN calculator is provided below.
PPLN calculator
What is PPLN?
Periodically Poled Lithium Niobate (PPLN) is a high efficiency nonlinear optical crystal for changing the wavelength (colour) of laser light. PPLN crystals can be used to mix and match a continuous range of wavelengths from 400nm to over 5000nm using a process called 'quasi-phase-matching'. Every PPLN crystal is based on an optical grating structure that synchronises the transfer of energy from a pump laser wavelength to a new chosen wavelength (or wavelengths) in this range.
PPLN is popularly used in a wide range of scientific and commercial applications, including; green laser display engines, blue and green wavelengths for material spectroscopy, broadly tunable mid-infrared systems for LIDAR and gas analysis, and terrahetrz wavelengths for non-invasive imaging.
What are the advantages of MgO doped PPLN?
Adding 5% Magnesium-Oxide to Lithium Niobate significantly increases the optical and photorefractive resistance of the crystal while preserving its high nonlinear coefficient. Magnesium-doped PPLN (MgO:PPLN or PPMgO:LN) provides better stability at visible wavelengths and higher powers and allows lower temperature operation than a similar undoped crystal. MgO:PPLN can be operated near room temperature for many applications.
