High-Transmittance Femtosecond Optical Kerr Gate with Double Gate Pulses Based on Birefringence Effect

Zhenqiang Huang,Xun Hou,Wenjiang Tan,Shijia Zeng,Jinhai Si,Zhen Kang

doi:10.3390/photonics9020071

Abstract

An optical Kerr gate (OKG) is an ultrafast optical switch based on the optical Kerr effect. The performance of a conventional OKG depends mainly on Kerr materials. Traditional Kerr materials do not demonstrate both large optical nonlinearity and an ultrafast response time. Therefore, the performance of a conventional OKG is limited by an inherent trade-off between high signal transmittance and fast switching time, which limits its application in many fields. We propose an improved femtosecond OKG with double gate pulses, based on the use of a birefringent crystal to realize an ultrashort switching time, even with a slow-response optical Kerr medium. We assessed the dependence of the double gate pulsed OKG (D-OKG)’s performance on the intensity ratio of the double gate pulses. A transmittance of 50% and a switching time of 142 fs were achieved. The D-OKG is convenient to construct, and its integrated performance is superior to that of a conventional OKG.

Highlights

A femtosecond optical Kerr gate (OKG) is an ultrafast optical switch based on the optical Kerr effect, which is widely used to realize the switching of light on an ultrafast timescale
Thegate results of Several side lobes appear in the relaxation of the curves when g2:Ig1 is larger than 0.53 time-resolved double gate pulsed OKG (D-OKG) signals were obtained by adjusting the ODL at several light intensity
We proposed an improved D-OKG to achieve an ultrashort switching time even with a

Summary

Introduction

A femtosecond optical Kerr gate (OKG) is an ultrafast optical switch based on the optical Kerr effect, which is widely used to realize the switching of light on an ultrafast timescale. An OKG consists of two crossed polarizers around a nonlinear medium, which is opened by introducing a linear laser pulse through the nonlinear medium to introduce a transient birefringence. Idlahcen et al proposed a two-color dualwavelength experimental setup for ballistic imaging with a crossed-beam geometry, and a better image resolution was obtained using spectral filtering to eliminate noise from the gate pulse [14]. Purwar et al proposed a dual-wavelength, collinear OKG-based optical switch to overcome the disadvantages of the classical single-wavelength crossed-beam arrangement. This experimental setup reduces noise because of the scattering of the gate beam towards the detector and avoids the complexity of signal transmission through the system in the crossed-beam arrangement [15]

Methods

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Discussion

Conclusion