HEM® Ti:Sapphire laser optics are renowned for their high quality, demanded by the world’s top ultrafast laser laboratories

GTAT’s proprietary HEM® technology produces superior crystalline structures in crystal sizes up to 220 mm in diameter.  Ultrafast laser optics made from HEM® Ti:Sapphire crystals have transmitted wavefront values of 1/10th or better, and FOM values up to 1000.

Low damage HEM®  Ti:Sapphire laser materials are processed at GTAT’s optical fabrication facility with extremely tight geometries and crystal alignment.  All aspects of crystal quality and optical fabrication workmanship are verified with our specialized test and measurement equipment. We provide detailed quality reporting on the laser, optical and mechanical attributes of our HEM® Ti:Sapphire laser optics.

GTAT has worked with the international community of high-intensity laser experts to develop the current range of HEM:ti sapphire ultrafast laser optics.  We are proud to deliver 200 mm and 220 mm HEM® Ti:Sapphire laser optics in support of today’s leading-edge high-intensity laser facilities.

HEM® is a registered trademark of GTAT Corporation.

HEM® Ti:Sapphire

  • 220 mm in diameter
  • Excellent homogeneity
  • Superior Thermal Properties
  • High Figures of Merit (FOM)
  • No Bulk Scatter
  • High Laser Damage Threshold
  • Large sizes and highly doped material available
  • Alpha values @ 532 nm of 0.5-8.0/cm
Sapphire-78

Attributes

  • FOM (Figure Of Merit) Vs. Absorption – The HEM® process has been developed to maximize absorption @ 532 nm and reduce parasitic absorption at 800 nm, thereby delivering the highest FOM values in the industry. Each GTAT HEM® Ti:Sapphire crystal is tested for actual FOM values, and these values are known to be the highest in the industry, (up to 1000).
FOM
  • Tunability Range of HEM Ti:Sapphire – HEM® Ti:sapphire has a wide tunable range from 650 nm to 1200 nm with peak intensity at ~800 nm. The wide bandwidth of the material allows for short pulses and high repetition rates. Our Ti:Sapphire laser optics are offered in a range of titanium doping concentrations, (0.5 to 8.0 @ alpha 532 nm) which allows adjustment of overall path length designs to meet your total low power single pass absorption, (LPSP).
Absorption
  • Absorption / Fluorescence – Ti:Sapphire lasers are typically operated using π-polarization. This chart shows the absorption and fluorescence bands of HEM® Ti:Sapphire in π-polarization.
  • Brewster’s Angle Laser Crystals – Most of our smaller crystals are polished with Brewster’s angle ends to minimize reflection losses. Brewster’s angle is based on the index of refraction of the material. The index of refraction for Ti:Sapphire is ~1.76, resulting in ~60.4° Brewster’s angle. The accuracy of our C-axis rotation is tightly controlled to avoid laser modulation.
TiSapphire Brewster Cut Laser Crystal
  • Advanced laser polishing and high damage coatings – GTAT applies the most advanced polishing technologies to its high-power laser optics in order to create angstrom-level roughness with low sub-surface damage. We perform testing to ensure high and repeatable laser damage threshold values.
TiSapphireRod
  • Anti-Reflection Coating – GTAT offers advanced anti-reflection coatings for multipass amplifier crystals. Our coatings are engineered to provide maximum efficiency at the pump and lasing wavelengths. The AR coatings are successfully operating in the field with consistently high laser damage threshold results, allowing laser operators to calculate pump powers accurately, thereby maximizing power output with low risk of damage.
Reflection

Features

High quality HEM® Ti:Sapphire laser crystals begin with perfect crystalline structure and the correct 3+ valance electron state.  We ensure these requirements through our multiple-stage, rigorous inspection process, using state-of-the-art test and measurement equipment. We test our rods for absorption values, homogeneity, light scatter, FOM, flatness, and transmitted wave fronts. Each HEM® Ti:Sapphire laser rod is examined and verified utilizing advanced equipment and expert laser technicians. Total focus on quality and accuracy guarantees that our laser crystals dimensions, surfaces and crystalline structure provide the foundation for your laser platform’s high power levels and excellent beam profiles.

Applications

HEM® Ti:sapphire’s wide emission range, (650 nm to 1200 nm), high-power density pumping capability along with excellent thermal properties enable today’s high-intensity laser platforms. These facilities are creating the next generation of laser-based applications such as proton therapy, accelerator physics, nuclear physics, far-field physics, infrared spectroscopy and materials characterization. GTAT works closely with its customers to develop new crystal designs so that the ultrafast laser community can continue to advance the reliability and performance of their products.

TiSapphire_ApplificationLaserCrystal

Laser Damage Threshold Testing of Ti:Sapphire AR Coating

The test results below come from one of the periodic tests that GTAT performs on the AR coating used on HEM® Ti:Sapphire Amplifier Crystals. These results are representative of the damage threshold that can be expected with our coatings.

Test Sample

  • Test Type: laser damage threshold
  • Substrate Material: HEM Ti:Sapphire
  • Sample Size: 1″ diameter
  • Coating Type: AR

 Test Conditions

  • Test Wavelength: 532 nm
  • Angle of Incidence: 0º
  • Pulse Repetition Frequencies: 10 Hz
  • Polarization: linear
  • Test Beam Profile: TEM Pulsewidth, (FWHM): 10 ns Axial Modes: multiple S
  • Pit Diameter: 570 µm
  • Number of Sites: 80
  • Test Method: laser damage frequency
  • Exposure duration: 200 shots/site

Test Results

  • Damage Definition: plasma, increased He-Ne scattering, visible damage as observed using a
    100X Nomarski Brightfield Microscope.
  • Description of Results: part irradiated at 13.00 Jcm-2 with no damage in 10 sites
  • Laser Damage Threshold: calculated at 14.16 Jcm-2 peak fluence
  • Testing provided by Spica Technologies Inc.

Features and Highlights

Laser Crystals up to 220 mm in diameter

Many design options including rectangles, squares and your unique designs

Low damage polished plano-ends, Brewster's angle ends

Highest laser damage threshold coatings available

Path lengths ranging from 1mm to 75mm

Absorption values from 0.5 to 8.0 /cm @ alpha 532 nm

Request a Quote

Contact us for a quote on any of our highly-pure sapphire materials, and to discuss the best options for your specific application.
Request a Quote