Mid-infrared self-similar compression of picosecond pulse in an inversely tapered silicon ridge waveguide

Jinhui Yuan,Xinzhu Sang,Kangping Zhong,Yin Xu,Gerald Farrell,Chongxiu Yu,Zhe Kang,Binbin Yan,P K A Wai,Jian Chen,Kuiru Wang,Qiang Wu,Feng Li,Xian Zhou,Chao Mei,Xianting Zhang

doi:10.1364/oe.25.033439

Abstract

On chip high quality and high degree pulse compression is desirable in the realization of integrated ultrashort pulse sources, which are important for nonlinear photonics and spectroscopy. In this paper, we design a simple inversely tapered silicon ridge waveguide with exponentially decreasing dispersion profile along the propagation direction, and numerically investigate self-similar pulse compression of the fundamental soliton within the mid-infrared spectral region. When higher-order dispersion (HOD), higher-order nonlinearity (HON), losses (α), and variation of the Kerr nonlinear coefficient γ(z) are considered in the extended nonlinear Schrodinger equation, a 1 ps input pulse at the wavelength of 2490 nm is successfully compressed to 57.29 fs in only 5.1-cm of propagation, along with a compression factor Fc of 17.46. We demonstrated that the impacts of HOD and HON are minor on the pulse compression process, compared with that of α and variation of γ(z). Our research results provide a promising solution to realize integrated mid-infrared ultrashort pulse sources.

Highlights

Optical pulse compression technique is important for many applications, including optical communication, nonlinear microscopy, supercontinuum and frequency comb generations [1,2,3,4,5,6], etc
On chip high quality and high degree pulse compression is desirable in the realization of integrated ultrashort pulse sources, which are important for nonlinear photonics and spectroscopy
When higher-order dispersion (HOD), higher-order nonlinearity (HON), losses (α), and variation of the Kerr nonlinear coefficient γ(z) are considered in the extended nonlinear Schrödinger equation, a 1 ps input pulse at the wavelength of 2490 nm is successfully compressed to 57.29 fs in only 5.1-cm of propagation, along with a compression factor Fc of 17.46

Summary

Introduction

Optical pulse compression technique is important for many applications, including optical communication, nonlinear microscopy, supercontinuum and frequency comb generations [1,2,3,4,5,6], etc. In a 6.4 m nonlinearity increasing photonic crystal fiber (PCF) taper, a 1 ps pulse is self- compressed to 53.6 fs with low pedestal [3]. Self-similar compression of a pulse from 1 ps to 81.5 fs in a 6 cm long dispersion decreasing chalcogenide slot waveguide taper has been demonstrated by simulation [23]. Further compression under the self-similar scheme in such a slot waveguide is limited by the two-photon absorption (TPA) of the substrate material and higher-order dispersion (HOD). We propose an inversely tapered silicon ridge waveguide with a simple taper profile to realize exponentially decreasing dispersion profile for self-similar pulse compression.

Theoretical model and principle of self-similar pulse compression

Design of silicon ridge waveguide taper

Self-similar pulse compression in the waveguide taper

Conclusion