There are many reasons for using temperature control in nonlinear optical conversions. The main reason is to achieve Non-Critical Phase Match (NCPM) for crystals that can be temperature tuned to a point where phase matching direction shifts to one of the crystal axis.
NCPM is advantageous in getting superior beam quality and efficiency. It has larger acceptance angle and zero walk-off, which is critical for pump probe experiments or third harmonic generation where beam overlapping is required.
Other purposes of temperature controlling include minimising the grey tracking of KTP crystals; overriding the instability caused by laser heating; stabilising laser oscillation, etc.
Laser 2000 is able to supply crystals configured with oven and temperature controller as complete turnkey systems. Oven and temperature controllers are available for LBO, KNbO3, MgO: LiNbO₃, KD*P in NCPM applications and a special oven is available for thin-plate type crystal, for use with PPLN and PPLT. For further details, please contact Laser 2000.
Digital Temperature Controller and Crystal Oven