Open AccessMiniaturized integrating sphere light sources based on LEDs for radiance responsivity calibration of optical imaging microscopes
Author(s) -
Yangting Fu,
Xiangliang Liu,
Yingce Wang,
Yingwei He,
Feng Gao,
Houping Wu,
Cheng Zheng,
Ping Li,
Haitao Gan
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.403899
Subject(s) - radiance , integrating sphere , optics , microscope , responsivity , light emitting diode , materials science , calibration , aperture (computer memory) , radiometer , optoelectronics , photodetector , physics , quantum mechanics , acoustics
LED-based integrating sphere light sources (LED-ISLSs) in the size of typical microscope slides were developed to calibrate the radiance responsivity of optical imaging microscopes. Each LED-ISLS consists of a miniaturized integrating sphere with a diameter of 4 mm, an LED chip integrated on a printed circuit board, and a thin circular aperture with a diameter of 1 mm as the exit port. The non-uniformity of the radiant exitance of the LED-ISLSs was evaluated to be 0.8%. The normal radiance of the LED-ISLSs in the range of (5∼69) W m -2 sr -1 was measured with a standard uncertainty of 1.3% using two precision apertures and a standard silicon photodetector whose spectral responsivity is traceable to an absolute cryogenic radiometer. The LED-ISLSs were applied to calibrate the radiance responsivity of a home-built optical imaging microscope with a standard uncertainty of 2.6∼2.9%. The LED-ISLSs offer a practical way to calibrate the radiance responsivity of various optical imaging microscopes for results comparison and information exchange.