Cryostat Optical Fiber Bench for Fast Optical Detector Characterization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Characterizing optical detectors with multiple measurements such as radiometric, remanence, dark current, and spectral response is cumbersome and time-consuming due to the need for repeated displacement and vacuum/temperature adjustments across different test benches.
Innovation Solution
A single test bench using a cryostat with a single-mode optical fiber for luminous flux generation and measurement, allowing various measurements without displacing the detector, by connecting different luminous flux generation modules to the optical fiber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple separate test benches are used for radiometric, remanence, dark current, and spectral response measurements, then each measurement can be performed with dedicated equipment, but the overall measurement time increases significantly and the process becomes cumbersome
Solution Approach 1:
The patent combines multiple separate test benches into a single integrated test bench that can perform radiometric, remanence, dark current, and spectral response measurements using a single detector setup. The key merging elements include: a single cryostat housing the detector, a single optical fiber delivery system, and a single vacuum chamber, eliminating the need to repeatedly assemble and disassemble the detector between different test benches.
Solution Approach 2:
The test bench is designed with universal components that can serve multiple measurement functions. The optical fiber delivery system can deliver light for radiometric and spectral response measurements while also allowing dark current measurements by blocking light. The single cryostat and vacuum system support all measurement types without requiring separate environmental control systems for each measurement type.
2Reliability
If the detector is repeatedly placed under vacuum and cooled for each measurement, then the operating conditions can be maintained, but the process time increases by a factor of 5 to 10
Solution Approach 1:
The detector is placed under vacuum and cooled to operating temperature once at the beginning of the measurement sequence, before any measurements are taken. The cryostat is evacuated and cooled in advance, and the detector is mounted on the optical fiber while under vacuum. This preliminary preparation allows all subsequent measurements to be performed without repeating the time-consuming vacuum and cooling cycles.
Solution Approach 2:
The vacuum and cryogenic conditions are maintained continuously throughout the entire measurement sequence. The detector remains in the same vacuum-sealed cryostat environment for all measurements, allowing uninterrupted operation. The optical fiber can be manipulated and light sources can be changed without breaking the vacuum seal or warming the detector, enabling continuous measurement operations.
3Stability of the object's composition
If bulky elements like integrating spheres are used for light delivery, then homogeneous luminous flux can be achieved, but the device bulk and complexity increase
Solution Approach 1:
The patent replaces bulky mechanical light delivery systems (integrating spheres, complex optical tables, multiple mirrors) with a compact optical fiber-based delivery system. The optical fiber acts as a flexible, compact light guide that can deliver homogeneous luminous flux directly to the detector without requiring large integrating spheres or complex alignment mechanisms. The fiber optic cable itself serves as the light delivery medium, eliminating the need for separate light sources and optical components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient, rapid, and accurate performance characterization of optical detectors by eliminating the need for repeated vacuum/temperature adjustments and reducing bulk, while maintaining measurement precision.
Implementation Method 1
a single-mode optical fiber in the operating wavelength range of the detector, said optical fiber being inserted into an opening of the cryostat, and comprising: a first end secured to an opening of the screen, to project a luminous flux onto all or part of the detector
Implementation Method 2
the detector having to be cooled at very low temperatures, typically in the range from 50 to 200 K
Implementation Method 3
a cryostat comprising means for placing it under vacuum and cooling it
Implementation Method 4
quantum-type detector... detectors implementing quantum phenomena operating at low temperature
Data Source
AI summary
A device for measuring the performance of an optical detector includes a cryostat, a holder capable of receiving the detector, secured to the inside of the cryostat, and means for measuring the performance of the detector. It also includes a screen arranged around the holder capable of limiting the radiation likely to reach the holder in a wavelength range of the detector, and a single-mode optical fiber in the wavelength range of the detector, inserted in an opening of the cryostat. The device further comprises at least one luminous flux generation module that incorporates a fibered source capable of generating the luminous flux in the optical fiber.