RTP The new crystal RTP is an isomorph of KTP. However, it has higher damage threshold (about 1.8 times KTP), higher resistivity, and no sign of electro- chromism.These are Biaxial crystals and natural Birefringence needs to be compensated by use of two crystal rods specially oriented so that beam passes along the X-direction.

The Q-switch is built using two RTP elements in a temperature compensating design. Input beam is polarized along the diagonal of the input face and Z and Y axis are perpendicular to the two side faces. Y and Z faces are rotated by 90° in the second crystal for thermal compensation.

The ¡®o' ray in the first crystal becomes the ¡®e' ray in the second crystal and vice versa, so that the thermal birefringence is compensated. Matched pairs (equal lengths polished together) are required for effective compensation.

The effective E-O constant r c1 (light propagating along the Y axis) is 23.6 pm/V and E-O constant r c2 (light propagating along the X axis) is 20.3 pm/V. The contrast ratio is better for r c2 constant. At repetition rates of 50KHz, the noise due to piezo-electric ringing is less than 3% while that in BBO it is 10% when operated at 30KHz.

An excellent crystal for Electro Optical applications at high repetition rate.
High Damage Threshold.
No Piezoelectric Ringing.
Low Insertion Loss.
Thermal Compensating Design.
Non-hygroscopic.
Not induce piezo-electric effect.