Search query: External optical feedback effects on semiconductor injection laser properties

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abstract: Influences on the semiconductor laser properties of external optical feedback, i.e. return of a portion of the laser output from a reflector external to the laser cavity, have been examined. Experimental observations with a single mode laser is presented with analysis based on a compound cavity laser model, which has been found to explain essential features of the experimental results. In particular, it has been demonstrated that a laser with external feedback can be multistable and show hysteresis phenomena, analogous to those of non linear Fabry Perot resonator. It has also been shown that the dynamic properties of injection lasers are significantly affected by external feedback, depending on interference conditions between returned light and the field inside the laser diode.
author_names: R S Lang

Kohroh Kobayashi
title: External optical feedback effects on semiconductor injection laser properties
year: 1980

abstract: External cavity, strong optical feedback, semiconductor lasers are analyzed using a rotated ellipse gain(REG) model. The model considers laser diode characteristics as well as the effects of optical feedback. Theoretical calculations on this strong feedback structure are developed in terms of amplification, injection locking, and mode ratio. Threshold current is expressed as a function of wavelength and temperature. Also various formulae for threshold current reduction, effective current, amplified output power, and reduced spectral linewidth are presented. From the amplified output power we calculate the spectral linewidth. We analyze in more detail the theoretical work of Patzak et al and show that spontaneous emission is reduced by frequency selective strong optical feedback. In designing external cavity lasers with strong feedback, mode ratio has to be larger than 100 for stable output power and frequency. It is possible to obtain many characteristic properties of the solitary laser diode with the help of the REG model.
author_names: I Oh

Harish R D Sunak
title: Analysis and Design of External Cavity, Strong Feedback, Semiconductor Lasers for Use with Coherent Optical Communication Systems
venue: Other Conferences
year: 1987

abstract: The authors study numerically the response of a single mode semiconductor laser under modulation of the injection current in the presence of optical feedback, for different external cavity lengths and feedback reflectivities. For an external reflectivity larger than R/sub ext/1.6*10/sup 4/ feedback degrades the statistical properties of optical pulses considerably. When the external round trip time is equal to the period of the modulation of the laser the optical pulses differ widely from each other and then they are not adequate for use in optical communication systems. In almost no case do we obtain better pulses than the corresponding ones in the absence of feedback. As happens in the solitary laser case, pattern effects, due to random sequences of inputs '0' and '1' bits, play an important role.
author_names: Claudio R Mirasso

Emilio Hernandez-Garcia

Jaume Dellunde

M C Torrent

Jose M Sancho
title: Current modulation and transient dynamics of single mode semiconductor lasers under different feedback conditions
year: 1995

abstract: In this paper, a new model of self pulsating semiconductor lasers (SPLs) is proposed based on the analogies between a SPL and a laser oscillator. In fact a SPL is first of all an oscillator even though it is difficult to identify amplifiers and feedback elements. The use of such analogies allows in some conditions to establish a very simple rate equation model of SPLs. One of the advantages of the model is the ability to analyze the injection locking properties of SPLs under external optical signal injection. In particular, it has been found that (1) the frequency looking range is directly proportional to the power ratio, (2) the spectral linewidth is equal to that of the incoming signal in the locking state. These points have been verified experimentally on a distributed feedback SPL. Nevertheless, a SPL is different from a laser in that the self pulsation signal can be short pulses as well as sinusoidal. The short pulses nature means that there are higher order harmonics created by nonlinear effects related to the laser operation. These higher order harmonics can be taken into account in our new model, which becomes however more complex.
author_names: Guang-Hua Duan

Guillaume Pham
title: New model of self pulsating semiconductor lasers
venue: Photonics West
year: 1998

abstract: We numerically investigate the influence of an integrated filtered optical feedback on the behavior of a semiconductor ring laser subject to external optical injection. The optical injection is spectrally directed at one of the non lasing longitudinal modes of the laser. This so called side mode injection can cause wavelength switching, directional switching, and changes in the dynamical regime of the semiconductor ring laser. Such changes are often unwanted as they can affect the stability and the performance of the semiconductor ring laser. We investigate to what extent these undesired effects can be avoided by stabilizing the laser using on chip filtered feedback. A two directional mode model is used to investigate the dynamical behavior of the semiconductor ring laser under the simultaneous effect of the external optical injection and the integrated feedback. The results show that on chip filtered optical feedback can be used to reduce the sensitivity of the semiconductor ring laser to external optical injection.We numerically investigate the influence of an integrated filtered optical feedback on the behavior of a semiconductor ring laser subject to external optical injection. The optical injection is spectrally directed at one of the non lasing longitudinal modes of the laser. This so called side mode injection can cause wavelength switching, directional switching, and changes in the dynamical regime of the semiconductor ring laser. Such changes are often unwanted as they can affect the stability and the performance of the semiconductor ring laser. We investigate to what extent these undesired effects can be avoided by stabilizing the laser using on chip filtered feedback. A two directional mode model is used to investigate the dynamical behavior of the semiconductor ring laser under the simultaneous effect of the external optical injection and the integrated feedback. The results show that on chip filtered optical feedback can be used to reduce the sensitivity of the semiconductor ring laser to external optica.
author_names: Mulham Khoder

Guy van der Sande

Guy Verschaffelt
title: Reducing the sensitivity of semiconductor ring lasers to external optical injection using selective optical feedback
year: 2018

abstract: Photonic Integrated Circuits (PIC) have become key elements to perform broadband transmission and reception functions in optical communication networks. This thesis provides information on hybrid semiconductor lasers (SCL) consisting of an active layer of III V materials on a silicon on insulator (SOI) substrate to jointly explode the emitting properties of III V layers and the numerous advantages offered by Si for on chip applications. Due to the significant technological developments in electronics, this hybrid approach is well positioned to meet the high volume requirements for short distance transmission and access networks at a lower cost. However, several challengest still exist such as the lack of effective light sources and isolator free devices. From a monolithic perspective of a PIC hetereogeneous integration, it is essential to ensure that the parasitic reflections that may stem from multiple locations do not affect the stability of the laser. Specifically, III V hybrid components on Si appear to have many potential sources of reflections that can create centimeter external cavities in addition to those naturally produced inside the fiber in the order of several meters. Therefore, the work presented herein aims at understanding the behavior of III V/Si SCLs when subjected to a variation of optical feedback, explores the basics aspects of chaotic dynamics, and investigates potential applications suitable for optical telecommunication systems in an attempt to meet the existing an emerging high speed requirements.
author_names: Sandra Gomez
title: Effects of dynamics and optical feedback on hybrid III V/Si semiconductor lasers
year: 2020

abstract: The temperature and external optical feedback (OFB) effects on power characteristics of external cavity semiconductor laser model based fiber Bragg gratings (FBGs) are numerically analyzed. In this model, fiber Bragg grating (FBG) is used as a wavelength selective element to control the properties of the laser output by controlling the external OFB level. The study is performed by modifying output laser equations that are solved by considering the effects of ambient temperature (T) variations and external OFB. In this study, the temperature dependence (TD) of laser characteristics is calculated according to TD of laser parameters instead of using the well known Pankove relationship. Results show that by increasing the external OFB level, the laser output power improves significantly. Also, results show that by changing the operating temperature 15 (from 15 to 30) there is no great impact on the output characteristics. The obtained results can provide an important idea for the practical fabrication for this type of lasers.
author_names: Hisham Kadhum Hisham
title: Numerical Analysis of the Effect of Temperature and External Optical Feedback Variation on the Output Characteristics of External Cavity Semiconductor Laser Based Fiber Bragg Gratings
year: 2015

abstract: The knowledge of the linewidth enhancement factor (aH factor) is very important to understand the performance of semiconductor lasers. It affects several fundamental aspects such as the linewidth, the laser's behavior under optical feedback, the chirp under direct modulation and the occurrence of the filamentation. The dramatic variation in the (aH factor that has been reported for quantum dot lasers makes them an interesting subject for optical feedback studies. In the particular case of QD lasers, the carrier density is not clearly clamped at threshold. The lasing wavelength can switch from the ground state to the excited state as the current injection increases meaning that a carrier accumulation occurs in the ES even though lasing in the GS is still occurring. The purpose of the paper is to show that the exploitation of the nonlinear properties arising from quantum nanostructure based semiconductor lasers operating under external optical feedback can lead, under specific conditions, to a bifurcation of the modulation properties. Starting from the generalized rate equations under optical feedback, the laser's modulation response is determined. Under the short external cavity assumption, calculations show that large variations of the (aH factor can contribute to improve the dynamical properties such as the relaxation frequency as well as the laser's bandwidth. On the contrary, assuming the long external cavity situation, numerical results show that even small reflections in the percent range when combined to significant variations of the (aH factor alter the laser's modulation response.
author_names: Frederic Grillot

Nikhil Dubey
title: Influence of the linewidth enhancement factor on the modulation response of a nanostructure based semiconductor laser operating under external optical feedback
venue: OPTO
year: 2011

abstract: The properties of injection locking chaos synchronization and communication in closed loop external cavity semiconductor lasers (ECSL) subject to phase conjugate feedback (PCF) are investigated systematically. We theoretically analyze the general conditions for the injection locking, and numerically investigate the properties of injection locking chaos synchronization in the phase and intensity domains, the influences of frequency detuning and intrinsic parameter mismatch on the injection locking chaos synchronization, as well as the performance of injection locking chaos synchronization based communication in closed loop PCF ECSL systems. The numerical results demonstrate that with respect to the conventional optical feedback (COF) scenario, the injection locking chaos synchronization in a PCF ECSLs configuration shows a significantly wider high quality synchronization region and excellent feasibility, and the performance of chaos communication can also be enhanced.
author_names: Ning Jiang

Anke Zhao

Shiqin Liu

Yiqun Zhang

Jiafa Peng

Kun Qiu
title: Injection locking chaos synchronization and communication in closed loop semiconductor lasers subject to phase conjugate feedback.
venue: Optics express
year: 2020

abstract: We present a numerical analysis that focuses, for the first time to our knowledge, on the feedback induced dynamics in a semiconductor passively mode locked laser with sub wavelength resolution. Our results and the corresponding theoretical explanations elucidate several aspects of the laser dynamics under self injection including inherent properties of mode locked lasers such as pulse intensity noise and timing jitter. We show that the dynamics of the laser exhibit a periodicity in the wavelength scale apparent only on integer multiples of the laser cavity and decays in the time scale of the pulse duration following the coherence of the mode locked laser. The corresponding phenomena are dominant for external cavities that are shorter than the laser cavity and superimposed on the previously reported dynamics of the semiconductor mode locked lasers for longer external delays. Since these dynamics are triggered by low feedback levels, our study could be useful for the optimization of the laser operation in cases where ultra short external cavity lengths are involved (integrated designs, power collection with fiber tapers, etc.
author_names: Christos Simos

Hercules Simos

Dimitris Syvridis
title: Sub wavelength resolution dynamics of semiconductor passively mode locked lasers induced by optical feedback
year: 2017