Crystals and optics processing services

ZnSe is used widely for IR components, windows and lenses, and applied for Thermal Imaging, FLIR,  Medical systems and Co2 Laser Zinc Selenide (ZnSe) Windows are ideal for a wide variety of infrared applications including thermal imaging, FLIR, and medical systems.

Nd:GdVO4, is a promising material for diode pumped lasers. Similar to the more well-known Nd:YVO4 crystal, Nd:GdVO4 crystal also exhibits high gain, low threshold, and high absorption coefficients at pumping wavelengths. Nd:GdVO4 has the additional advantage over Nd:YVO4 of a much higher thermal conductivity. For CW lasing at 1.06 um and 1.34 um and intracavity doubling with KTP and LBO, the gadolinium vanadate have produced a higher slope efficiency or optical conversion than Nd:YVO4.

Ti:Sapphire crystal is the most widely used tunable solid-state laser material combining the supreme physical and optical properties with the extremely broad lasing range. Its lasing bandwidth can support pulses < 10fs making it the crystal of choice for femtosecond mode-locked oscillators and amplifiers. The absorption band of Ti:Sapphire centers at ~ 490 nm so it may be conveniently pumped by various laser sources such as argon ion lasers or frequency doubled Nd:YAG, Nd:YLF, Nd:YVO4 lasers at ~530nm. Laser designers are using Ti:sapphire to generate femtosecond pulses to create new industrial tools. A properly delivered femtosecond laser pulse interacts within the target leaving the surrounding area undisturbed. Newly developed femtosecond pulsed lasers micro-machine complex fine structures in glass, metal and other materials. Active waveguides can be written below the surface, integrating optical devices within the body of a substrate. Defects in photomasks can be repaired without disturbing neighbouring patterns. And it is now possible to achieve cellular resolution in vivo for medical diagnosis with femtosecond pulse lasers.

Germanium (Ge) is the preferred lens and window material for high performance infrared imaging systems in the 8–12 um wavelength band.

Cr4+:YAG (Y3Al5O12) crystal is ideal for passive Q-switch operation of Nd:YAG and other Nd3+ or Yb3+ doped laser crystals in the wavelength range of 900 nm to 1200 nm. Passive Q-switches or saturable absorbers provide high power laser pulses without electro-optic Q-switches, thereby reducing the package size and eliminating a high voltage power supply. A remarkable feature of Cr4+:YAG is the high damage threshold of >10 J/cm2@1064 nm, 10 ns. Its absorption band extends from 900 nm to 1200 nm and peaks around 1060 nm with a very large absorption cross-section.

Ytterbium-doped Potassium Gadolinium Tungstate (Yb:KGd(WO₄)₂, Yb:KGW) crystal is an excellent laser gain material, boasting numerous advantages over the widely used Nd³⁺-doped materials. Its wide spectral emission band of 1023-1060 nm enables the generation of short laser pulses (picosecond or femtosecond level). The broad absorption band at 980 nm and highly absorbent pump radiation allow it to efficiently utilize diode laser pumping. Compared with YAG doped with Yb³⁺ ions, KGW crystal has a larger absorption cross-section, which reduces the minimum pump intensity required to achieve transparency in the quasi-two-level system of Yb.

Silicon is used as an optical window primarily in the 3 to 5 micron band and as a subsrate for production of optical filters and windows.     Silicon (Si) is grown by Czochralski pulling techniques (CZ) and contains some oxygen that causes an absorption band at 9 microns. To avoid this, material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped (5 to 40 ohm cm) for best transmission above 10 microns, and doping is usually boron (P-type) and phosphorus (N-type). After doping silicon has a further pass band: 30 to 100 microns which is effective only in very high resistivity uncompensated material.    

BK7 window is the most common type of window. It has good performance over visible and near infrared wavelength regions. At the same time, BK7 window is ideal for applications require minimal transmitted beam deviation. It is suitable for AR coating.