We use a planar linear grating with varied line-space grooves to introduce a tailored one-dimensional phase variation profile that results in an aberrated point-spread function at the focal plane. A design procedure for the period chirp map for such gratings is developed. As an example, we present theoretical and experimental results on a mechanically ruled, varied line-space echelle grating in single-mode fiber-coupled optical multiplexers in the wavelength region of 1545 nm. The varied line-space grating changes the multiplexer's Gaussian spectral response function to a flat-top dependence with reduced sensitivity to source laser wavelength drift.
© 2007 Optical Society of America
Diffraction and Gratings
Original Manuscript: July 7, 2006
Revised Manuscript: September 5, 2006
Manuscript Accepted: September 11, 2006
X.-P. Huang, Scott M. Spuler, and Andrew D. Sappey, "Varied line-space grating for flat spectral response of coupling to single-mode fiber," Appl. Opt. 46, 147-153 (2007)