Our Femtokits are designed for efficient third harmonic generation (THG) of femtosecond Ti:Sapphire laser. They consist of a set of optical components and nonlinear frequency conversion crystals carefully chosen to achieve the best configuration for frequency tripling for different ranges of laser pulse durations of fundamental harmonic.

Femtokits for THG can also be supplied as a complete solution with opto-mechanics required for quick set up (please have a look at mounted Femtokits in the product list below).

Reference:
up to 50% SHG conversion efficiency was achieved in 0.5 mm SHG BBO crystal with Ti:Sapphire Super Spitfire laser operating at 1 kHz, 130fs, 20-100 µJ @800nm and effective beam diameter 0.9 mm. THG efficiency reached up to 8% from fundamental using FKE-800-100 Femtokit.

Basic Femtokit FK Series includes following components mounted into 1 inch ring holders:

• Type 1 second harmonic generation (SHG) BBO crystal, P-coated @ 400-800 nm
• Type 1 third harmonic generation (THG) BBO crystal, P-coated @ 400-800/266 nm
• Calcite plate for group velocity delay compensation, AR coated @ 800+400 nm
• Zero order waveplate, λ/2@800+λ@400 nm, optically contacted, AR coated @ 800+400 nm 

Extended Femtokit FKE Series includes following components mounted into 1 inch holders:

• Type 1 2nd harmonic generation (SHG) BBO crystal, P-coated @ 400-800 nm
• Type 1 3rd harmonic generation (THG) BBO crystal, P-coated @ 400-800/266 nm
• Calcite plate for group velocity delay compensation, AR coated @ 800+400 nm
• Zero order waveplate, optically contacted, λ/2@800+λ@400 nm, AR coated @ 800+400 nm
• Zero order waveplate, optically contacted, AR coated @ 800 nm
• Harmonic Separator, HR @ 266 nm and HT @ 800+400 nm at AOI=45 deg
• Harmonic Separator, HR @ 400 nm and HT @ 800 nm at AOI=45 deg
• Laser mirror, HR @ 800 nm at AOI=45 deg

The thickness of SHG BBO crystal, THG BBO crystal and group delay compensation plate is different in each kit and is optimal for certain pulse duration of fundamental harmonic to avoid harmonic pulses broadening.