Ti:Sapphire, or titanium-doped sapphire, is a laser gain material used in tunable and ultrafast systems. When comparing crystals, specify the pump conditions, figure of merit (FOM), geometry and optical interfaces together. A material parameter alone does not establish the output power or pulse duration of the finished laser.
What does Ti:Sapphire FOM mean?
FOM compares absorption in the pump region with residual absorption in the laser-emission region. The wavelengths used in that ratio must be stated. Values measured at different wavelengths or polarization conditions should not be treated as directly interchangeable.
Research by Miller and Zidek on FOM measurement found that crystal inhomogeneity and polarization alignment relative to the crystal axis can affect the measured result. Ask for the measurement method, sampling position and uncertainty when FOM is a purchase acceptance requirement.
Specify the pump and cavity requirements
Provide the actual pump wavelength and beam conditions rather than relying only on a nominal dopant concentration. Crystal length, pump absorption, end geometry, coatings and thermal mounting should be reviewed against the intended oscillator or amplifier design.
Direct diode pumping is an established research topic: a diode-pumped Kerr-lens mode-locked Ti:Sapphire laser was reported in 2012. That demonstration does not establish compatibility with every diode source or crystal. A proposed design still needs its own optical and thermal evaluation.
Ti:Sapphire quotation checklist
| Requirement | Information to provide |
|---|---|
| Laser configuration | Tunable CW laser, oscillator or amplifier; intended operating wavelength |
| Pump conditions | Wavelength, power or pulse energy, beam size and operating mode |
| Absorption and FOM | Required values, reference wavelengths and agreed measurement conditions |
| Crystal geometry | Dimensions, orientation, clear aperture and tolerances |
| End faces and coatings | Flat or Brewster geometry; coating wavelengths and incidence angles |
| Inspection and delivery | Required inspection records, quantity and target schedule |
Review the crystal specification with ATR
See the Ti:Sapphire crystal product specifications for the options currently described by ATR Crystal. Final material availability, FOM requirements and inspection scope must be confirmed for the quotation.
Send your drawing and pump specifications through our technical sales contact page. For other gain materials, browse the laser crystal range.
Technical references
- Miller and Zidek, High-precision FoM measurement setup for Ti:Sapphire crystals, 2023. Author manuscript; the research results are not ATR batch inspection data.
- Direct diode-pumped Kerr-lens mode-locked Ti:sapphire laser, Optics Express, 2012. A research demonstration under the authors’ experimental conditions.