Transition Edge Superconducting Bolometers
One of the largest linear dynamic ranges available!
Wide optical window (0.1 - 30 THz)
Full broadband detection up to 3 KHz
Can be arrayed
Available in wet or dry systems
Transition edge superconducting (TES) bolometers, are an incredibly sensitive broadband detector, offering a higher sensitivity, greater linear dynamic range, lower susceptibility to background noise and a faster speed compared to more traditional Germanium/Silicon bolometers. Their operating principle relies on channelling EM radiation onto an absorber, causing its energy to be deposited as heat. This propagates through the semiconducting crystal until it reaches a superconducting ring, which is operated at a temperature where it is making the transition from the normal state to the superconducting (zero resistance) state. The resistance thus changes sharply over a very small temperature range, making it an extremely sensitive thermometer. This resistance is monitored by the read-out system.
The bolometer is most commonly mounted in an optical integrating cavity behind a Winston Cone coupling optics along with low-pass filters which ensure that unwanted higher frequencies are efficiently rejected. It is important that the field of view of the coupling optics be matched to the incoming beam geometry. This ensures not only that all available signal power is available for detection but also that the bolometer is not unduly de-sensitised by exposure to an unnecessarily high background power.
Our TES bolometers are always sold complete with our own cryogenic systems, filters and electronics to ensure it performs as specified (we are however flexible and are happy to consider integrating a detector into existing cooling platform). Cooling can be provided either by a mechanical (pulse tube) cooler or by liquid helium. Mechanically cooled systems are complete and require only an electricity supply to operate.
Our liquid helium bath cryostats are designed and built to our specifications by our sister company, Thomas Keating Ltd. These cryostats offer the convenience of very long run-times. Cryostat operation is straightforward, and detector systems come with a comprehensive range of safety devices as standard. Superior cryogenic performance allows significant long-term saving on the cost of liquid helium. Larger cryostats are suitable for multi-channel detector systems or when very long liquid helium hold times are required.
Each detector system is evaluated and designed on an individual basis to provide optimum performance in all applications. Direction of view, throughput, field-of-view, filter selection, cryogenic performance and many more aspects of the detector system can be custom designed often at no extra cost.
Notes on specification
The high frequency limit of the range of a bolometer system is set by low-pass filters mounted at both 77 K and 4.2 K. We offer a range of standard filters with transmission edges at 0.3, 0.6, 1, 2, 3, 6, 10, 13.5 and 18 THz (10, 20, 33, 66, 100, 200, 300, 450 and 600 cm-1 respectively).