KTP (Potassium Titanyle Phosphate – KTiOPO4)
KTP (Potassium Titanyle Phosphate – KTiOPO4) efficiency, high damage threshold and ease of handling makes KTP one of the most widely preferred crystals for laser applications in the medical, industrial, defence and scientific fields.
The main applications for KTP are Second Harmonic Generation (SHG) in the visible spectral range and Optical Parametric Oscillations (OPO) for the tunable near infrared spectral range.
It is well known that most of flux-grown KTP crystals suffer from blackening and efficiency breakdown ("grey-track") when used during SHG process of 1064nm at high average power levels and repetition rates above 1 kHz. According to KTP users, grey-track gives rise to harmonic power unstability (for many intracavity doubling cw laser), efficiency drop and crystal blackening (for high power-high repetition rate laser) and sometimes the process is accompanied by beam distorsion (when the beam is strongly focused within the crystal).
For this reason, Cristal Laser has developed KTP.fr ("fully resistant") on the basis of modified fluxes which allow an improvement in the stoechiometry within the KTP crystal lattice. As a consequence, this material exhibits a much better resilience to grey-track. Recent improvements now enable us to process components with apertures up to 10x10mm² and with a length above 10mm.
KTA (Potassium Titanyle Arsenate – KTiOAsO4)
KTA (Potassium Titanyle Arsenate – KTiOAsO4) is an excellent optical non-linear crystal mainly developed for Optical Parametric Oscillation(OPO).
While being comparable to KTP in terms of non-linear efficiency and ease of use, the main advantage of KTA material over KTP consists in a significantly reduced absorption in the 3-4 µm range.
RTP (Rubidium Titanyle Phosphate – RbTiOPO4)
RTP (Rubidium Titanyle Phosphate – RbTiOPO4) is a material now widely used for Electro Optical applications whenever switching voltages are required to be low.
Moreover, the lack of piezo-electric ringing also makes it possible to use RTP for Q-switching at high repetition rates or pulse-picking of fast pulsetrains.
This material is non hygroscopic and fairly resilient to laser damage.
LBO (Lithium triborate - LiB3O5)
Over the last few years LBO crystal has become a material of choice for high power laser applications from the UV to NIR.
LBO (Lithium triborate - LiB3O5) is now the most popularly used material for Second Harmonic Generation (SHG) of 1064nm high power lasers (as a substitute to KTP) and Sum Frequency Generation (SFG) of 1064nm laser sources to achieve UV light at 355nm.
LBO crystal also has the advantage that it can be used in Non Critical Phase-Matching configuration (no walk-off) at certain temperatures(around 150°C for SHG of 1064nm). Recent development of our crystal growing technique now allows us to process crystals with apertures of several cm².
BBO (Beta-BaB2O4) has been used for years in non-linear optics (mainly for scientific applications) and electro-optics, due to its excellent damage threshold, outstanding bulk homogeneity and transmission in the UV for wavelenghts up to 200nm.
Cristal Laser grows this material since 2008 and we are in the process of adapting our polishing methods to it as we expect the demand for BBO to increase.