NARROW BANDWIDTH VOLUME HOLOGRAPHIC OPTICAL FILTER OPERATING AT THE KR TRANSITION AT 1547.82-NM

We describe and characterize a narrow bandwidth volume holographic opt ical filter operating at the Krypton transition line (1s2-2p8) at 1547 .82 nm, which corresponds to the center wavelength of the proposed Int ernational Telecommunications Union wavelength standard. A reflectivit y of 98% and a bandwidth full width at half-maximum of 0.18 nm are mea sured. The filter exhibits clean sideholes with a -20 dB optical respo nse 0.5 nm away from the peak. The filter can be fabricated and operat ed with an absolute wavelength precision better than 0.005 nm.