Available Technology

Photonic calorimeter and process for performing calorimetry

The invention is a photonic device whose resonance characteristics (such as, quality factor, peak position, and free spectral range) change in a predictable way in response to the interaction of radiation with the sensor and/or its surroundings. The invention can be used in an offline mode, in which cumulative dose can be quantified. Another version of the invention can be used to measure real-time dose by making a differential measurement using two or more photonic sensors having different sensitivities to cumulative radiation dose.

Patent Abstract: 

A photonic calorimeter converts ionizing radiation dose to heat and includes: a radiation absorber, a temperature compensator disposed within the radiation absorber, a compensation waveguide, a compensation resonator, a compensation resonator, a thermal isolator on which the radiation absorber is disposed and that thermally isolates the radiation absorber from heat loss by thermal transfer due to physical contact by an object, and the temperature compensator changes the optical resonance of the compensation resonator in response to a change in temperature of the radiation absorber due to absorption of the ionizing radiation by the radiation absorber.


This invention works in harsh environments where electronic dosimeters could fail. Size scale is smaller than the state of the art, so can be used for dosimetry of microscopic samples, surfaces and regions of large dose gradients (e.g. near beam penumbrae or near boundaries of dissimilar materials within bulk matter).


Ronald Tosh, Zeeshan Ahmed, Ryan P. Fitzgerald, and Nikolai Klimov

Patent Number: 
Technology Type(s): 
Manufacturing, Ionizing Radiation, Photon Physics, and Precision Measurement
Internal Laboratory Ref #: 
Patent Issue Date: 
September 22, 2020
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