Passive Chaos Bandwidth Enhancement Under Dual-Optical Feedback with Hybrid III–V/Si DFB Laser

Abstract

The chaotic dynamics of a DFB laser are studied ex-5 perimentally under a combination of short and long feedbacks. 6 Chaos bandwidth enhancement is demonstrated using a hybrid 7 III-V/Si DFB laser with a large relaxation oscillation frequency 8 (ROF) of 14 GHz. The impact of short feedback on the ROF is Q1 9 studied and an increase of 2 GHz is observed. Under long feed-10 back, the route to chaos of the device and its dependence on the 11 short feedback dynamics are studied. The short feedback allows 12 tuning the chaotic dynamics obtained under long feedback, and the 13 increase of the ROF translates into an enhancement of the chaos 14 bandwidth to above 16 GHz. This configuration can allow gener-15 ation of wideband chaos using a single laser source in a photonic 16 integrated circuit. 17 Index Terms-III-V materials, nonlinear dynamics, optical feed-18 back, silicon photonics, secure communications. 19 I. INTRODUCTION 20 S ILICON photonics offer tight integration of a variety of 21 active and passive optical and electrical components, and 22 gained so much interest in the last decade that it is now con-23 sidered one of the most promising technology for optical appli-24 cations [1], [2]. Building on the mature fabrication techniques 25 first developed for microelectronics allows creating photonic 26 integrated circuits (PICs) with a high density of optical compo-27 nents, in high volumes and at low costs. Academic and industrial 28 efforts led to the development of novel technical solutions for 29 a variety of domains including sensing, measurement instru-30 mentation, optical signal processing and telecommunications 31

Wideband chaos from a laser diode with phase-conjugate feedback

“…To increase the chaos bandwidth beyond that limit, several sophisticated setups have been proposed. Experimentally, wideband chaotic semiconductor lasers have been achieved using optical feedback from two external cavities (16 GHz) [10], optical injection in a slave laser with feedback (16 GHz and 17 GHz) [11,12], dual-wavelength injection into a laser with optical feedback (32 GHz) [13] or three lasers with optical feedback, injecting each others (35 GHz) [14]. Recently, replacing a conventional mirror by a phaseconjugate mirror, i.e.…”

Review on the broadband time‐delay‐signature‐suppressed chaotic laser

“…44 The flatness refers to the range of spectrum fluctuation within the bandwidth. In order to eliminate the influence of relaxation oscillation frequency on the bandwidth and flatness of chaotic laser, researchers have carried out extensive studies, including improved optical feedback, [45][46][47][48][49][50] unidirectional optical injection, [51][52][53][54][55][56][57][58][59] mutual injection, 60,61 and subsequent processing 62,63 of chaotic laser.…”

Mid-infrared free-space cryptosystem

“…This method is easy to implement and allows high-speed private fibred communication up to dozens of Gbits/s and hundreds of kilometers [16]. This feat is made possible because of the large chaos bandwidth exhibited by many semiconductor lasers [17], such as laser diodes and VCSELs. QCLs are intersubband semiconductor lasers and consequently, they do not exhibit relaxation oscillations [18].…”