Swept-source digital holography to reconstruct tomographic images.
We present what we believe to be a new method of swept-source digital holography using a superluminescent diode (SLD) as a broadband light source and an acousto-optic tunable filter (AOTF) as a frequency tunable device. The swept source consists of an SLD as a broadband source in conjunction with the AOTF as the frequency tuning device in the wavelength range of 800-870 nm. Since the AOTF is an electronically controlled device, frequency tuning can be achieved without mechanical movement . The angular spectrum approach to the scalar diffraction theory is used to reconstruct the images for each wavelength. Applications of a broadband source ensure an increased axial resolution of reconstructed images. The proposed swept-source system provides a sufficiently broad range of tunability and can increase the axial range and the resolution of reconstructed tomographic images using digital holography. The system was tested using a semireflecting glass substrate; a character "B" is written on it with black ink. Experimental results are presented.
Sheoran
Gyanendra
G
Laser Applications and Holography Laboratory, Instrument Design Development Centre, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110 016, India.
Dubey
Satish
S
Anand
Arun
A
Mehta
Dalip Singh
DS
Shakher
Chandra
C