Multichannel Fiber-Optic Spectral Streak Equalizer

摘要

Spectral-streak equalization is a technique that has been developed to compensate for the material dispersion in optical fibers when used in conjunction with an electronic streak camera. Material dispersion occurs because different wavelengths of light travel at different speeds through glass fibers; the resulting difference in transit time broadens light pulses, and can lead to errors in high bandwidth photonic measurements. An instrument designed to compensate for this effect has been in use for the past several years in systems used to evaluate underground nuclear tests. A new instrument has been developed that has the following advantages: it can equalize several channels with one set of optics; it uses considerably less space; it has better resolution and greater efficiency, and it is more cost effective. This paper reviews the basic principles, describes the equalizers currently in use, discusses the design considerations of the new equalizer, describes a prototype four channel instrument, details efficiency estimates, outlines calibration procedures, and gives test results. (ERA citation 11:054713)