Our bolometer systems each offer advantages to best meet your spectral band, frequency response, noise, budget, and cryogenic or cryogen-free cooling requirements. We have decades of experience customizing configurations to meet your specific application requirements including longer hold times, increased work height, dual detectors, filter positions, coupling options, and more.

Bolometer Systems Table


Spectral Response (µm)

Operating Temp
Electrical Sensitivity (S[V/W] Noise Equivalent Power
Frequency Response
(Optimum Chopping Frequency)
Liquid Cryogen Cooling

Cryogen-free Cooling

General Purpose 4.2 K Bolometer System

15 – 2000

operation to 4.2 ~ 2.4 X 105 ~ 2.5 X 10-13 ≤ 80 at 80Hz < 500 Hz    
Hi Res 4.2K Bolometer System

15 – 2000

operation to 4.2 ~ 6.1 X 105 ~ 6.5 X 10-14 ≤ 40 at 80Hz < 200 Hz    
Standard 1.6 K Bolometer System

15 – 2000

1.6  ~ 7.5 X 105 ~ 4.6 X 10-14 ≤ 40 at 80Hz > 1 KHz    
Far-IR 1.6 K Bolometer System

300 – 5000

1.6 ~ 1.0 X 107 ~ 3.6 X 10-15 ≤ 50 at 80Hz < 300 Hz    

InSb Hot e-Bolometer

0.2mm – 5mm

4.2 > 4.0 X 103  < 8 x 10-13 < 4.0 at 200Hz < 600 kHz    
Bolometer Systems

Cryogenic Bolometers

Closed Cycle Bolometers

Cryogen-free Bolometers

What is a bolometer?

Bolometers are detectors used to measure incident IR radiation. They are very sensitive to thermal radiation and are predominantly used in the IR spectrum between 10 to 5000µm (30THz to 60GHz). The detector element is an extremely sensitive thermistor that is cooled to LHe temperatures to decrease the thermal background. Any thermal radiation that impinges upon the detector will cause a temperature change. This will cause a change in resistance which is amplified and measured as a voltage difference.

Because bolometers measure a change in temperature, the incident radiation must be modulated. This allows the bolometer to excite and relax, thus a measurement of the change in resistance is made that corresponds to the energy of the incident radiation. The speed at which the bolometer reacts to this temperature change is dependent upon several factors that can be altered, if desired, at the time the system is ordered.

Cooled using liquid cryogens or cryo-free mechanical refrigeration.

Bolometers are cooled to cryogenic temperatures using pour-filled liquid cryogen dewars or cryogen-free mechanical refrigeration. Liquid cryogen coolers are compact with no moving parts, easy to use, have a lower initial cost, and recommended for simple, reliable operation. Refrigerated systems are larger, more complex, and have a higher initial cost but eliminate the expense of refilling cryogens. Cryo-free cooling is recommended for cost-effective, continuous unattended cold operation:

Contact Us to Spec Cooling

Bolometer Systems

  • General Purpose 4.2K Bolometer System
    Versatile 4.2 K bolometer

    Our most popular and versatile bolometer system covers a wide range of applications. It consists of a 4.2 K  bolometer detector element bonded to a 2.5mm diamond absorber. It operates best in the range of 15 to 2000µm (20THz to 150GHz) with modulation frequencies in the 200 to 400Hz range.  Available in liquid cryogen or cryogen-free cooling options.

  • Hi Res 4.2K Bolometer System
    4.2 K bolometer with lower thermal conductivity and higher resolution

    This system provides a lower thermal conductivity detector and increased spectral resolution. The configuration offers a slower responding system with modulation frequencies best kept below 200Hz. This system is more sensitive with NEP values an order of magnitude lower than the general purpose 4.2 K system. Available in liquid cryogen or cryogen-free cooling options.

  • Standard 1.6K Bolometer
    Higher sensitivity and quick response time operating at 1.6 K

    Similar to our general purpose 4.2 K system in spectral response (15 to 2000µm) with added benefits of lowering the temperature of the detector: lower NEP, higher sensitivity, and a quick response time. This system can work at modulation frequencies greater than 1 KHz.

  • Far-IR Bolometer
    Detects lower energy signals in the longer wavelengths of the IR spectrum at 1.6 K

    Specifically configured to detect the lower energy signals present in the longer wavelengths of the IR spectrum with optimal performance from 300µm to 5mm. It has a very low thermal conductivity to aid longer integration times to capture low signal strengths and is best operated at modulation frequency less than 300Hz.

  • InSb Hot e-Bolometer
    High speed and sensitive 4.2 K bolometer

    When cooled to liquid helium temperatures, absorption of radiation by free carrier electrons causes the mean temperature of the electrons (To) to rise above that of the host lattice. Electron mobility is proportional to To3/2, hence this temperature rise can be sensed as a change in conductivity. The very low thermal mass of the free electrons, coupled with short energy relaxation times of about 107 seconds, leads to a very fast and sensitive sub millimeter wave detector. This detector uses a specially shaped high purity N-type InSb crystal which may be coupled directly to a very low noise preamplifier. Available in liquid cryogen or cryogen-free cooling options.