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Published on: April 7, 2023
A passive long-wavelength infrared microscope with a highly sensitive phototransistor
Yusuke Kajihara1, Susumu Komiyama, Patrick Nickels
1Department of Basic Science, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
The Review of Scientific Instruments
|July 2, 2009
Summary
A novel passive scanning confocal microscope uses a highly sensitive charge-sensitive infrared phototransistor (CSIP) detector for long-wavelength infrared (LWIR) imaging. This technology enables clear imaging of spontaneous LWIR radiation with high spatial resolution.
Area of Science:
- Optics and Photonics
- Infrared Spectroscopy
- Materials Science
Background:
- Long-wavelength infrared (LWIR) imaging is crucial for various applications.
- Developing sensitive passive imaging systems for LWIR radiation remains a challenge.
- Existing microscopy techniques may lack the required sensitivity or spatial resolution in the LWIR spectrum.
Purpose of the Study:
- To develop a passive scanning confocal microscope for sensitive LWIR imaging.
- To utilize an ultra-highly sensitive charge-sensitive infrared phototransistor (CSIP) detector.
- To demonstrate the capability of the developed microscope for spontaneous LWIR radiation imaging.
Main Methods:
- Construction of a passive scanning confocal microscope using room-temperature (Ge objective lens) and liquid helium temperature (confocal pinhole, Ge relay lenses, CSIP detector) components.
- Imaging of spontaneous thermal radiation at a wavelength of 14.7 micrometers.
- Achieving a spatial resolution of 25 micrometers.
Main Results:
- Obtained clear passive LWIR imaging of various materials including glass, Al foil, Ag paste, and Au.
- Successfully imaged samples even when their surfaces were covered by GaAs or Si plates.
- Demonstrated high-quality passive LWIR imaging with the developed system.
Conclusions:
- The developed passive scanning confocal microscope is effective for sensitive LWIR imaging.
- Charge-sensitive infrared phototransistor (CSIP) detectors show significant promise for passive LWIR microscopy.
- This technology offers a new avenue for high-resolution, sensitive imaging in the long-wavelength infrared spectrum.
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