Open AccessResonant cavities based on Parity-Time-symmetric diffractive gratings
Author(s) -
Mykola Kulishov,
Bernard C. Kress,
Radan Slavı́k
Publication year - 2013
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.009473
Subject(s) - optics , distributed bragg reflector , fiber bragg grating , bragg's law , lasing threshold , refractive index , reflection (computer programming) , coupled mode theory , diffraction grating , diffraction , grating , distributed bragg reflector laser , physics , materials science , optoelectronics , laser , computer science , programming language
We explore a new class of Distributed Feedback (DFB) and Distributed Bragg Reflector (DBR) structures that employ the recently-developed concept of Parity-Time (PT) symmetry in optics. The approach is based on using so-called unidirectional Bragg gratings that are non diffractive (transparent) when illuminated from one side and diffracting (Bragg reflection) when illuminated from the other side, thus providing a uni-directional Bragg functionality. Such unusual property is achieved through diffraction through a grating having periodic variations in both, phase and amplitude. DFB and DBR structures traditionally consist of a gain medium and reflector(s) made via periodic variation of the (gain media) refractive index in the direction of propagation. As such structures are produced in a gain material. It becomes just possible to add periodic amplitude modulation in order to produce the unidirectional Bragg functionality. We propose here new and unique DFB and DBR structures by concatenating two such unidirectional Bragg gratings with their nonreflective ends oriented outwards the cavity. We analyze the transmission and reflection properties of these new structures through a transfer matrix approach. One of the unique characteristics of the structure is that it inherently supports only one lasing mode.