Semi-imaging light pipe for collecting weakly scattered light

George W. Hopkins; Tad D. Simons

doi:10.1117/12.321993

21 September 1998 Semi-imaging light pipe for collecting weakly scattered light

George W. Hopkins, Tad D. Simons

Proceedings Volume 3482, International Optical Design Conference 1998; (1998) https://doi.org/10.1117/12.321993
Event: International Optical Design Conference, 1998, Kona, HI, United States

Abstract

A simple reflective light pipe, formed from a cylindrical tube with an external reflective coating and a small central aperture, can be a highly efficient optical element for collecting light from molecular scattering processes along the path of a laser beam. When the laser beam is co-linear with the axis of the light pipe, scattered light from any location along the interaction region (near the pipe axis) re-images repeatedly to another location along the axis of the pipe. This semi-imaging property of the light pipe permits a large fraction of the total scattered light to re- image along the entire length of the interaction region. If one observes through the small central aperture, scattered light from the single segment of the laser beam in view appears to come from all the locations along the interaction length, as well as from the single segment. In this manner, one can have the advantage of collecting scattered light from a small segment (and thus onto a small detector), while observing an effective interaction length that is many times longer than the segment. Measurements from practical light pipes confirm effective gains of about 10X with light pipes a few centimeters long (Effective gain is defined as the ratio of light collected with the light pipe divided by the light collected from a direct image of the beam using the collection optics).

Citation Download Citation

George W. Hopkins and Tad D. Simons "Semi-imaging light pipe for collecting weakly scattered light", Proc. SPIE 3482, International Optical Design Conference 1998, (21 September 1998); https://doi.org/10.1117/12.321993

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