Periodic bandpass filter with near-ideal filter response based on Sagnac loop interferometer.

In this paper, an analytical analysis is made on a periodic bandpass filter formed by a two-cavity etalon incorporated into a Sagnac loop interferometer. The general optimum conditions for a quasi-flat-top spectrum and a ripple-free group-delay response are derived. Our results show that by properly choosing the reflectance of the mirrors, the filter can be designed with a quasi-flat-top spectral response that is also free from group-delay ripples. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 17–21, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20194 [ABSTRACT FROM AUTHOR]