PowerLocker® Wavelength Stabilization Gratings

Ondax’s PowerLocker® wavelength stabilization gratings are volume holographic gratings (VHGs) that “lock” a laser diode’s emission wavelength into a narrowed optical spectrum. This increases the spectral brightness and delivers highly stablized optical performance over extended temperature ranges. PowerLockers® typically reduce the spectral output of a laser by an order of magnitude. The short external cavity configurations enabled by the PowerLocker® design deliver better mode selection than systems based on Littrow or Littman cavities, at a fraction of the size and cost.

All Ondax VHGs are bulk “solid-state” diffractive holographic filters made from a proprietary photosensitive optical glass, which unlike thin films or gels, can deliver ultra-stable, degradation free performance over an unlimited lifetime. Capable of very tight wavelength, efficiency, bandwidth, and diffraction angle control, Ondax VHGs can be precisely and reproducibly engineered to meet even the most demanding spectral and temporal specifications.

Proprietary materials, manufacturing and test processes ensure consistent, repeatable performance from every single filter, every time, guaranteed.



  • Increases spectral brightness of lasers
  • Reduces thermal dependence of lasers
  • Reduces unwanted spectral components
  • Ultra-narrow bandwidth
  • Low loss
  • Highly stable and reliable
  • Over 30,000 hours of testing at >200°C
  • No degradation under high power illumination conditions


  • Wavelength Stabilization of Diode Lasers for Optical Pumping and Instrumentation
  • Notch and ASE Filters for Raman Spectroscopy
  • Beam Combining
  • Rb/Atomic Laser pumping
  • Pulse Stretching and Compression
  • Augmented Reality (AR)
  • Metrology
  • Sensing
  • Bio-instrumentation
  • Lung Imaging
PowerLocker® Operating Specifications
Parameter Min Typical Max Unit
Center Wavelength 375 405, 658, 780.25, 785, 794.7, 808, 885, 920, 938, 976, 981, 1064, 1532, C-band 2700+ nm
Wavelength Tolerance1 -0.5 +0.5 nm
Wavelength Variation (within filter) 0.2 nm
Bandwidth2 (FWHM) 0.03 1 nm
Temperature Dependence 0.01 nm/˚C
Bragg Mirror Reflectivity 5 10-98 >99.9 %
Reflectivity Tolerance1 -5 +5 %
Grating Slant Angle <1 (Custom Available) degs
Standard Dimensions (X,Y) 0.5 25 mm
Thickness 0.3 0.6-3 30 mm

1Tighter tolerances available
2Grating bandwidth is a function of wavelength and thickness

Laser Wavelength Stabilization with PowerLocker®

Adding PowerLocker® to an external cavity laser system enables wavelength stabilization of the output, increasing the power in the desired mode and reducing unwanted spectral components.

Unstabilized without PowerLocker®

Unstabilized without PowerLocker®

Wavelength Stabilized with PowerLocker®

Measured Performance with and without PowerLocker®

Measured Performance with and without PowerLocker®

Model Number System
Model Number System