ORC-Cylindric
ORC-Cubic
Optical Reference Cavity

MENLO Ultrastable Laser Systems ORC Cavities 3w

Specifications

Advanced Features and Benefits

Ultrastable optical reference for laser frequency stabilization
Compact footprint
Highly customizable – entire portfolio available as building blocks

	ORC-Cubic	ORC-Cylindric
Wavelength	500–2000 nm	500–2000 nm
Finesse	low / mid / high	low / mid / high
Cavity Length	5 cm	12.1 cm
Free Spectral Range	3 GHz	1.24 GHz
Windows	AR coated, angled and wedged	AR coated, angled and wedged
Thermal Shields	active and passive	active
Linear Drift Rate	~150 mHz/s	~150 mHz/s
Ambient Temperature Sensitivity	~4 mK/°C	~4 mK/°C
Temperature Sensor	10 kΩ NTC	10 kΩ NTC
Peltier Elements	2x 25 W	1x 56 W
Ion Getter Pump	5 l/s	10 l/s
Achievable Pressure	< 10^-7 mbar	< 10^-7 mbar
Stainless Steel Valve	Cu sealed, KF flange	Cu sealed, CF flange
Dimensions	W 28 cm, L 28 cm, H 18 cm	W 48 cm, L 35 cm, H 35 cm
Vacuum Chamber Material	aluminum	stainless steel
Mass	15 kg	55 kg
Rack Integration	n.a.	n.a.

Description

The Optical Reference Cavity (ORC) series is our solution when customization is pivotal. Choose from the exceptional portfolio of adaptations, auxiliary instruments and services and profit from our experience in designing generations of ultrastable laser systems.

The ORC family are Fabry-Pérot-type cavities with a resonator spacer made out of ultra-low expansion glass (ULE). The cavity is mounted in a sealed vacuum housing, engineered for exceptional temperature stability to enable low frequency drift. The compact design ensures minimal spatial demand. It is based on a rigidly mounted cubic spacer licensed from National Physical Laboratory. The ORC-Cylindric uses a cylindric spacer designed by the Physikalisch Technische Bundesanstalt, that is horizontally mounted on four support points. Here, portability is ensured by a mechanical locking mechanism.

A broad variety of add-ons and options is available for customization. The highly reflective coatings are available over a broad wavelength range and also as dual or triple highly reflective mirrors. Modules for input coupling, PDH locking, and output monitoring can be rigidly mounted onto the chamber, rendering tedious realignments after transportation obsolete.

Every system is baked-out during the assembly process. The built-in NTC and Peltier elements are accessible via vacuum feedthroughs, allowing for operation at the zero crossing of the coefficient of thermal expansion (CTE). Characterization of the CTE is available on request. Both cavities are also available without enclosure.

Reference Cavity Spacers:

Options

Optics Module for Input Coupling, PDH Locking, and Monitoring

Product Code: ORC-OPTIC-CUB / ORC-OPTIC-CYL
Two modules holding all optics required for input coupling one single wavelength to the cavity in the range from 633 to 1560 nm, Pound-Drever-Hall locking as well as power monitoring of the transmitted light. The modules are rigidly mounted onto the cavity housing making realignments after transportation obsolete.
Optics Module for Input Coupling, PDH Locking, and Monitoring

Product Code: ORC-OPTIC-DUAL
Complementary optics mounted on the ORC-OPTIC-CUB/ORC-OPTIC-CYL module for coupling a second laser wavelength in the range from 633 to 1560 nm simultaneously to the same cavity. This add-on requires the ORC-OPTIC-CUB/ORC-OPTIC-CYL option.
ORC Mirror Coatings for Multiple Wavelengths Package

Product Code: ORC-MWL
For the simultaneous stabilization of multiple lasers to the same reference cavity, custom coating designs and cavity mirrors which are highly reflective at two or multiple wavelengths can be tailored to your application.
TEC Driver Package

Product Code: ORC-TEC
A TEC driver to stabilize the temperature of the reference cavity to the zero-crossing temperature of the coefficient of thermal expansion.
PDH Optics

Product Code: ORC-PDH-Optics
Fiber-coupled compact optical unit for the generation of the PDH reflection signal.
Pound-Drever-Hall Servo Electronics Package with TEC controller

Product Code: ORC-SYNCRO
For stabilizing the laser to the cavity, this package provides all required electronics in a single configurable device, i.e., Menlo’s SYNCRO controller (3rd generation). The SYNCRO provides full software control of all parameters and intuitive use via touchscreen. This 3U, 19-inch device can also be remotely accessed via LAN. The package includes phase modulation and demodulation, and a fast analog PI²D controller (>10 MHz bandwidth) providing two servo outputs for fast and slow actuators and a TEC controller for temperature stabilization.
Pound-Drever-Hall Servo Electronics Package with TEC controller and 1542 / 1550 nm Laser Module

Product Code: ORC-SYNCRO-RLD
For stabilizing the laser to the cavity, this package provides all required electronics in a single configurable device, i.e., Menlo’s SYNCRO controller (3rd generation). The SYNCRO provides full software control of all parameters and intuitive use via touchscreen. This 3U, 19-inch device can also be remotely accessed via LAN. The package includes phase modulation and demodulation, and a fast analog PI²D controller (>10 MHz bandwidth) providing two servo outputs for fast and slow actuators, a TEC controller for temperature stabilization and a laser module at 1542 or 1550 nm.
Characterization of the Zero-Crossing Temperature

Product Code: ORC-CTE
Determining precisely (within 50 mK) the zero-crossing temperature of the coefficient of thermal expansion (CTE) of the ULE reference cavity is fundamentally important for stable operation. This procedure requires a dedicated measurement infrastructure and is very time consuming due to the long thermalization time constant. Menlo routinely characterizes the CTE zero-crossing temperature, allowing you to dedicate more time to your application.