The Measurement Of Optical Coherence Loss In Atlantic Waters

William J. Stachnik

doi:10.1117/12.956861

10 November 1978 The Measurement Of Optical Coherence Loss In Atlantic Waters

William J. Stachnik

Proceedings Volume 0160, Ocean Optics V; (1978) https://doi.org/10.1117/12.956861
Event: 22nd Annual Technical Symposium, 1978, San Diego, United States

Abstract

This paper describes optical coherence loss and very small angle forward scatter mea-surements performed in Atlantic coastal waters. The technique used to measure coherence loss involved the use of an argon-ion laser source and a self-aligning interferometer capable of projecting two confocal beams to ranges of approximately 10 and 20 meters. The interference patterns formed at the common focal point of these beams were used to determine the normalized degree of coherence at spatial frequencies ranging from 10,000 to 100,000 cycles/radian. The measurement of very small angle forward scatter was also accomplished using the argon laser source. However, instead of using two apertures to produce two interfering beams, a single 50 mm aperture was used. The results of these measurements for Florida waters show that coherent optical behavior is present at all spatial frequencies measured. The response (i.e., the value of the normalized degree of coherence) tends to fall at the higher spatial frequencies, but often this behavior is dominated by significant temporal variations. Very small angle forward scattering experiments (1-300 microradians) have provided some insight into these temporal variations. These measurements show in-water beam diameters varying between 3 and 10 times their diffraction limited spot diameters within relatively short time intervals. Also observed in these experiments was a granulation (spatial spiking) of the beam at very small angles. This granulation possesses a scale size approximately equal to that of the diffraction limited spot size of the 50 mm source aperture used in this test. The optical parameters of the water, its T-S microstructure, and other oceanographic parameters were also recorded.

Citation Download Citation

William J. Stachnik "The Measurement Of Optical Coherence Loss In Atlantic Waters", Proc. SPIE 0160, Ocean Optics V, (10 November 1978); https://doi.org/10.1117/12.956861

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available