Tailoring and tuning of the broadband spectrum of a step-chirped grating based frequency doubler using tightly-focused Gaussian beams
Research Area: Uncategorized Year: 2013
Type of Publication: Article  
Authors:
  • Ameneh Bostani
  • Meenu Ahlawat
  • Amirhossein Tehranchi
  • Roberto Morandotti
  • Raman Kashyap
 
Journal: Optics Express Volume: 21
Number: 24 Pages: 29847-29853
Month: September
   
Abstract:
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 >5nm, with a beam waist of 20 ┬Ám. 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.
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