Open AccessNon-diffracting beam generated from a photonic integrated circuit based axicon-like lens
Author(s) -
Rijan Maharjan,
Sanket Bohora,
Pravin Bhattarai,
Iain F. Crowe,
Richard J. Curry,
Richard A. Hogg,
David Childs,
Ashim Dhakal
Publication year - 2021
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.419618
Subject(s) - axicon , optics , grating , materials science , optoelectronics , silicon on insulator , lens (geology) , photolithography , laser , physics , silicon , laser beams
We demonstrate an on-chip silicon-on-insulator (SOI) device to generate a non-diffracting beam of ≈850 µm length from a diffractive axicon-like lens etched using a low resolution (200 nm feature size, 250 nm gap) deep-ultraviolet lithographic fabrication. The device consists of circular gratings with seven stages of 1x2 multimode interferometers. We present a technique to apodize the gratings azimuthally by breaking up the circles into arcs which successfully increased the penetration depth in the gratings from ≈5 µm to ≈60 µm. We characterize the device's performance by coupling 1300±50 nm swept source laser in to the chip from the axicon and measuring the out-coupled light from a grating coupler. Further, we also present the implementation of balanced homodyne detection method for the spectral characterization of the device and show that the position of the output lobe of the axicon does not change significantly with wavelength.