Systems and Hardware for Cavity-Stabilized Lasers

Cavity Housings and Temperature Stabilized Enclosures

Mounting and temperature control are key to the performance of a high-finesse Fabry-Perot cavity.

We offer a line of vacuum housings designed to optimally mount and control products from Advanced Thin Films, the industry leader in high-finesse cavities. The outer layer of the vacuum housing is a thermally insulated, radiation-shielded shell that mounts to an optical table using standard clamps. The inner layer of the vacuum housing is conductive, with Peltier coolers and/or heaters for milli-Kelvin-level temperature control and thermistors for sensing. The internal mounting structure is designed to keep vibration sensitivity to a minimum. All of our vacuum cans offer exceptional temperature control for low frequency drift over a wide range of temperatures.

We offer standard housings for various Fabry-Perot cavity spacer geometries, including cylindrical and notched (Vacuum Housing 6010/6020), midplane (Vacuum Housing 6030), and spherical (Vacuum Housing 6300). Please click here for detailed discussion of cavity spacer geometry performance. We also provide variations on these standard housings, including tetrahedral mounting geometries, hermetically sealed enclosures, double-stage temperature control, and more. Please scroll down for details.

Vacuum Housing 6010/6020 – Cylindrical and Notched Cavities

Designed for use with the ATFilms 6010-(1 thru 3) or ATFilms 6020-(1 thru 3) cavity. It offers moderate thermal insulation leakage over an intermediate temperature range.

This housing is a well-matched cradle for either the ATFilms 6010 cylindrical cavity or ATFilms 6020 notched cavity, offering temperature control of <7 mK/C for low frequency drift over a 15-40 C range. Thermally insulated and radiation-shielded, the aluminum housing mounts to an optical table using standard clamping forks. Two Peltier coolers or heaters provide temperature control, and thermistors are used for sensing. The mounting structure within is optimized for rigidity and low thermal expansion, makes use of common-mode techniques to reduce deformation, and provides some degree of vibration isolation. We start with our field-proven design and then build each vacuum housing to order, taking into account your specific application and needs.

While a cylindrical cavity is the simplest design, notches decrease vibration sensitivity via common mode rejection of acceleration. Notched cavities are recommended for linewidths below 100Hz, and the mounts have Viton supports at the points calculated to minimize the acceleration sensitivity. For the best performance from a standard cavity spacer, we recommend a notched spacer with Fused Silica mirrors and ULE backing rings.

Full specification (pdf) ➤

Fabry-Perot cavity
Fabry-Perot cavity in vacuum housing

A notched Fabry-Perot cavity (Advanced Thin Films 6020-4), on a Zerodur mounting block, being guided into place in a thermally insulated vacuum housing. Lower image is shown with optional gold coated radiation shield.

Vacuum Housing 6030 – Midplane Cavity

This housing is a well-matched cradle for the ATFilms 6030 midplane cavity, offering temperature control of <5 mK/C for low frequency drift over a 17-30 C range. Thermally insulated and radiation-shielded, the aluminum housing mounts to an optical table using standard clamping forks. A Peltier cooler or heater provides temperature control, and thermistors are used for sensing. The mounting structure is optimized for rigidity and low thermal expansion, makes use of common-mode techniques to reduce deformation, and provides some degree of vibration isolation. We start with our field-proven design and then build each vacuum housing to order, taking into account your specific application and needs.

Frequency drift depends on how close to the zero-crossing temperature the cavity is operated. To achieve an expansion coefficient of less than 2 ppb, one would typically want to work within 1 degree of the zero-crossing temperature.

Full specification (pdf) ➤

Fabry-Perot cavity

A midplane Fabry-Perot cavity (ATFilms 6030) on a mounting plate.

Vacuum Housing 6300 – Spherical Cavity

This housing is a well-matched cradle for the ATFilms 6300 spherical cavity, offering temperature control of <5 mK/C for low frequency drift over a -5 through 50 C range. Thermally insulated and radiation-shielded, the stainless steel housing mounts to an optical table using standard adjustable-height base clamps. A Peltier cooler provides temperature control, and thermistors are used for sensing. The mounting structure within is optimized for rigidity and low thermal expansion, makes use of common-mode techniques to reduce deformation, and provides some degree of vibration isolation. We start with our field-proven design and then build each vacuum housing to order, taking into account your specific application and needs.

A spherical cavity offers several advantages. Clamped into the vacuum housing using a yoke, its geometry offers low vibration sensitivity, which may improve even further as mounting techniques improve. Temperature control can be better for smaller vacuum housings, and our method of implementation within the housing gives this unit the best thermal insulation leakage and widest operating range of all our vacuum housings. The cavity is firmly held, and can be moved while mounted.

Full specification (pdf) ➤

Housing for Fabry-Perot cavity

The vacuum housing for an Advanced Thin Films spherical cavity (ATFilms 6300). The gold plated shield (behind the anti-reflection coated viewport) allows milliKelvin levels of temperature control.

Transportable Cavity Systems

To maximize experimental versatility, our stable cavities do not have to be stationary fixtures anymore. Pictured is a vacuum housing with ultra-high vacuum rotary clamp feed through. This allows the cavity to be clamped to the mounting block, protecting the cavity and preserving alignment while keeping the system under vacuum during a gentle move. Tested on the flood-damaged roads of Boulder, Colorado in the fall of 2013!

A Fabry-Perot vacuum housing with clamp ready to be moved

A vacuum housing with clamp to allow the cavity to be clamped to the mounting block while being moved.

Tetrahedral Cavity Mounts

Emerging applications require stable optical sources on moving platforms. Tetrahedral mounting designs offer superb three dimensional support. Enclosures are available for cubic (pictured) and spherical cavity spacers, with tetrahedral support points.

Fabry-Perot cavity mount

Tetrahedral Cavity Mounts

Hermetically Sealed Enclosures

These reduced complexity enclosures are designed for high performance while maximizing ease of use. Optical input and cavity transmission couple directly into fiber. The linewidth is ~ 100 Hz at 1 second and the cavity drifts ~ 300 kHz/day.

Sealed enclosure for Fabry-Perot cavity

Hermetically Sealed Enclosure

Dual Stage Temperature Stabilization

This beefy enclosure contains our standard temperature stabilized vacuum housing with a new twist: the standard enclosure is also temperature stabilized and isolated from the surroundings by another enclosure. This setup is designed to fight the thermal drift and gradients that remain a major source of long term frequency drift. Resulting cavity thermal stability is ~ 1 mK/day.

A Fabry-Perot vacuum housing with temperature control.

A vacuum housing with two stages of temperature control for mK/day control.