Fig. 17From: Integrated enhanced Raman scattering: a reviewAdapted with permission from Ref [65], Copyright © 2020, IEEEThe dashed curve is the measured back-scattered Raman spectrum with the waveguide mode excitation. The solid curve is the spectrum obtained for an oblique free-space excitation at an angle of 75°. The NTP Stokes peaks are highlighted by yellow shaded areas. Back to article page