We experimentally demonstrate highly efficient coupling into a slow light slotted photonic crystal waveguide. With optical mode converters and group index tapers that provide good optical mode matching and impedance matching, a nearly flat transmission over the entire guided mode spectrum of 68.8 nm range with 2.4 dB minimum insertion loss is demonstrated. Measurements also show up to 20 dB baseline enhancement and 30 dB enhancement in the slow light region, indicating that it is possible to design highly efficient and compact devices that benefit from the slow light enhancement without increasing the coupling loss.
© 2012 Optical Society of America
Original Manuscript: August 15, 2011
Revised Manuscript: November 15, 2011
Manuscript Accepted: November 27, 2011
Published: January 13, 2012
Che-Yun Lin, Alan X. Wang, Wei-Cheng Lai, John L. Covey, Swapnajit Chakravarty, and Ray T. Chen, "Coupling loss minimization of slow light slotted photonic crystal waveguides using mode matching with continuous group index perturbation," Opt. Lett. 37, 232-234 (2012)