Fe:ZnSe – Ferrum doped zinc selenide
Absorption 2.8 μm – 4.4 μm | Emission 3.4 μm – 5.2 μm
Fe:ZnSe or Iron(Ferrum) doped Zinc Selenide (Fe2+:ZnSe) is arguably one of the most effective crystals used to design lasers in middle (thermal) infrared. As it’s cousin Cr:ZnSe, this crystal exhibits high absorption coefficient which allows efficient pumping. That can be done in range of 2.8 – 4.4 μm, with pumping peak at ~3 μm. Some pumping suggestions bellow:
- Pump with Cr:CdSe, Cr:ZnSe lasers
- Flash pump using Er:YAG @ 2.94 μm, Er:YSGG @ 2.78 μm
Due to short lifetime of Fe:ZnSe material, 3photon suggest to limit pumping pulses to hundreds of nanoseconds. Ferrum zinc selenide crystal can be tuned and has very wide lasing (emission) range with a peak at approximately 4500 nm (4.5 μm).
Fe:ZnSe crystal acts as saturable absorber (passive modulator) for passive Q-switching.
3photon offers single crystal Fe:ZnSe with or without optical coatings.
- Applications in lasers
- Large absorption coefficient;
- Structure: cubic;
- Sizes: up to 40 x 40 x 50 mm;
- Emission range of 3.4 µm – 5.2 µm;
- Extensive gain bandwidth > 500 nm;
- Efficient performance at room temperature;
- Available various density number concentrations.
- As a gain material in compact laser systems;
- As passive Q-switch for 2800 – 3400 nm nm lasers;
- Source for pumping middle infrared (MIR) optical parametric oscillators (OPO);
- Infrared (IR) missile countermeasure systems (ship and aircraft based);
- Free space communications;
- Gas tracing and analysis;
- Chemical warfare detection;
- Non-invasive medical diagnostics;
- Medical surgeries;
- Cavity ring down (CRD) spectroscopy
Being (arguably) one of the best crystals for Middle Infra-red (MIR), Fe:ZnSe crystals are usually used in:
- Continues Wave (CW) Fe:ZnSe lasers (which can also be tunable as well as fixed)
- Gain-Switched (pulsed) Fe:ZnSe lasers (fixed or tunable)
- Free running Fe:ZnSe lasers
Currently most Iron doped Zinc Selenide (Fe:ZnSe) growers are using Chemical Vapor Deposition (CVD) technology to grow poly-crystalline material.
3photon Fe:ZnSe growers use other technologies and which can produce single crystal.