Cavities for second harmonic generation

Agile Optic's SHG cavities address a broad spectrum:

SHG spectrum

We offer resonant enhancement cavities for second harmonic generation for all purposes:

Frequency doubler

Common features of our cavities:

  • Monolithic frame:
    All optomechanics are integrated into a monolithic frame, which makes our cavities mechanically more robust than conventional free-space setups on breadboards.
  • Sealed housing:
    The housing comes with sealed windows and a lid and therefore protects the crystal from adsorbands and moisture.
  • Accessibility:
    The mirrors and the crystal holder are accessible with high-precision fine-threaded screws from outside the housing.
  • Thermal control:
    The crystal holder is equipped with a temperature sensor and a heating element to suppress condensation on the crystal facets and/or to achieve phase matching.
  • Length stabilization:
    The cavity length can be stabilized by electrical feedback on an piezoelectric actuator.
  • Extended diagnostics:
    One of the windows transmits a fraction of the circulating fundamental light for diagnostic purposes.
  • Cleanliness:
    The housing comes with connectors for gas purging to maintain a clean environment around the crystal, which is crucial for application in the UV.
  • Compatibility:
    All housings can be mounted directly on 25 mm and 1 inch thread-spaced optical tables and breadboards.

Cavity solutions:

Frequency doubler IR to VIS
IR to VIS standard cavity.
Application examples: SHG of 794 nm, 846 nm, 986 nm, 1064 nm, 1156 nm, or 1550 nm pump light.
Suitable for AR-coated PPLN and LBO crystals.
Compact dimensions due to 50 mm ROC mirrors.
Frequency doubler VIS to UV
VIS to UV standard cavity.
Application examples: SHG of 461 nm, 532 nm, 560 nm, or 626 nm pump light.
Suitable for Brewster-cut BBO or CLBO crystals.
Compact dimensions due to 50 mm ROC mirrors
Custom frequency doubler
Custom cavities.
We develop and build cavities for special demands, for instance large resonators with large beam waists for high-power applications.

Plug and play systems:

  1. We integrate the cavity plus all optomechanics and optics for incoupling and length-stabilization in a rigid box.
  2. We also add photodetectors to record an error signal and monitor the fundamental and SHG power.


Please have a look at our references.