Open AccessTailoring and tuning of the broadband spectrum of a step-chirped grating based frequency doubler using tightly-focused Gaussian beams
Author(s) -
Ameneh Bostani,
Meenu Ahlawat,
Amirhossein Tehranchi,
Roberto Morandotti,
Raman Kashyap
Publication year - 2013
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.21.029847
Subject(s) - optics , grating , apodization , ripple , wideband , chirp , bandwidth (computing) , broadband , materials science , sideband , narrowband , physics , laser , telecommunications , computer science , quantum mechanics , voltage , microwave
We demonstrate theoretically and experimentally, that the non-uniform spectra of second harmonic generation (SHG) from an unapodized step-chirped periodically poled nonlinear optical grating can be apodized utilizing tightly-focused Gaussian beams to suppress the ripple in its wideband response. In our example, by increasing focusing, a ripple-free response is progressively achieved over a 6-dB bandwidth of >5 nm, with a beam waist of 20 µm. With this tight focusing arrangement, a continuous tuning of 11-nm is also demonstrated by simply changing the focal point by 5.8 mm within the step-chirped grating based APPLN.