Open AccessPassive photonic integration of lattice filters for waveguide-enhanced Raman spectroscopy
Author(s) -
Nathan F. Tyndall,
Todd H. Stievater,
Dmitry A. Kozak,
Marcel W. Pruessner,
William S. Rabinovich
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.405864
Subject(s) - optics , photonics , waveguide , materials science , laser , detector , optoelectronics , photonic integrated circuit , raman spectroscopy , physics
To perform waveguide-enhanced Raman spectroscopy (WERS) or fluorescence spectroscopy in a compact device, the optical fibers to couple the passive photonic circuit to the laser source and detector require attachment directly to the die. This necessitates the integration of edge couplers and waveguide-based filters to isolate the fiber background emission from the on-chip signal, while efficiently coupling the pump laser and detector to the input and output fibers, respectively. In this work, we experimentally demonstrate the successful integration of four-port lattice filters with sensing spirals and inverse-taper edge couplers in a passive photonic circuit. We further show that the four-port lattice filter enables the collection of backscattered on-chip Stokes signal, improving and simplifying overall system performance.