Analysis of directdiscrimination of fsk modulated optical. Lau 1, xiaoxue zhao, hyukkee sung2, devang parekh, connie chang hasnain 1, and ming c. Bifurcation analysis of ordinary rate equations, describing noisefree lasers with pure coherent external signal, reveals that adjusting the extend and type of externallyinduced bifurcations and chaos to desired state is possible by tailoring of the laser active medium and resonator configurations. We experimentally investigate the dynamical characteristics of semiconductor lasers subject to both the optical injection oi and the optical feedback of. They form the backbone of the optical telecommunications infrastructure supporting the internet, and are used in information storage devices, barcode scanners, laser printers and many other everyday products. Introduction complex dynamical systems often exhibit extreme or rare events. For instance, injecting with an orthogonal polarization is not equivalent to nullify the effect of optical injection as demonstrated by our experimental map. The injection locking technique allows the lasers to exceed their fundamental modulation speed limit, allowing for greater communication speeds.
Short monochromatic optical pulses are easily produced with semiconductor lasers ps range gbs to tbs photons do not interact each other photons can be propagated in optical fiber with very low loss 0. Mechanisms for multistability in a semiconductor laser. With unique advantages of broad frequency tuning range and large sideband rejection ratio, p1 oscillations can be useful in applications such as photonic microwave generation, radiooverfiber communication, and. Sep 01, 2004 the two fundamental parameters are the detuning and the injected power. Sensitivity of semiconductor lasers to coherent and noisy. Optical injection locking oil as an applicable technique to modify the output characteristics of a semiconductor laser such as reducing the relative intensity noise and enhancing the side mode suppression ratio 22, 23 has also promising effects on modulation bandwidth and frequency chirp of semiconductor lasers. Semiconductor lasers stability, instability and chaos. Semiconductor lasers have important applications in numerous fields, including engineering, biology, chemistry and medicine. The opsl concept has two design advantages compared to conventional diodepumped solidstate lasers based on crystal gain mediums such as nd. As new laser gain mediums were developed, injection locking of the medium usually followed a few years later, as in co 2 lasers in 1972 30 and, importantly for.
Semiconductor lasers are wellknown as threedimensional nonlinear systems for electrical field e t, carrier densities n t and optical phase. Dec 18, 2006 recently, optical injection locking has been proven to enhance the bandwidth and resonance frequency of directlymodulated semiconductor lasers. Enhanced modulation dynamic performance of opticallyinjected. Since the semiconductor laser has unique features of high gain, low facet reflectivity, and amplitudephase coupling through the \\alpha \ parameter, it is also sensitive to optical injection from a different laser. In this study, we propose to use semiconductor lasers as frequency converters instead, where no probe or pump beam is necessary. Fromwx wx a theoretical point of view, a laser with optical injection is. We will consider only diode lasers showing one dominant frequency single mode. Lin et al nonlinear dynamics of semiconductor lasers under repetitive optical pulse injection 605 d. Semiconductor lasers subjected to external optical injection from a single mode tunable laser have been investigated in a masterslave con. To employ this locking technique successfully it is essential to know the stability boundaries for a laser subject to optical injection and to understand the underlying dynamical properties beyond these boundaries. We study the stability of periodone p1 oscillations experimentally generated by semiconductor lasers subject to optical injection oi and by those subject to optical feedback of.
Pdf multipulse excitability in a semiconductor laser. Li, a unified description of semiconductor lasers with external light injection and its application to optical bistability. We have experimentally demonstrated nearsingle sideband modulation in strong optical injection locked semiconductor lasers. Pdf fast phenomena in semiconductor lasers researchgate. The static solution of the rate equation reveals that the fm demodulation efficiency is independent of the optical injection level in the steady state. Alloptical frequency conversion using nonlinear dynamics of. The processing techniques and properties are described here in the last decade the semiconductor injection laser has become a mature device for use in various types of professional and consumeroriented optical systems. We characterize the sensing capability of the laser in terms of the amplitude and the duration of the perturbation. Strong optical injection locked semiconductor lasers demonstrating 100ghz resonance frequencies and 80ghz intrinsic bandwidths erwin k. As new laser gain mediums were developed, injection locking of the medium usually followed a few years later, as in co 2 lasers in 1972 30 and, importantly for this work, semiconductor lasers in 1980 31. Injectionlocked semiconductor lasers are very useful for stabilizing the laser, however they sometimes shows a rich variety of dynamics.
When a semiconductor laser is subject to an incoming optical carrier, equivalently an external optical injection, it can enter into periodone dynamics through hopf bifurcation. In soas photons were confined in the dimensions transverse to the waveguide but were allowed to escape from the end of the waveguide. Optimizing optically injected semiconductor lasers for periodic. Wu 1department of electrical engineering and computer sciences, university of california, berkeley, berkeley, california 94720, usa. Open access correlated random bit generation using. Introduction to support the growing need for larger transmission speeds in optical communications, much research has been devoted to increasing the direct modulation bandwidth of semiconductor lasers.
However, these lasers are very sensitive to external perturbations such as optical feedback, optoelectronic feedback or optical injection2,3. This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. For optical injection locking, we prepare two lasers with almost the same oscillation frequencies and the frequency detuning between them must. Danckaert department of applie d physics and photonics, vrije universiteit. Correlation properties and timeresolved dynamics of linear. Tunable photonic microwave generation using optically. A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Strong optical injection locking of edgeemitting lasers and. Optical injection in semiconductor or fiber lasers. The term laser originated as an acronym for light amplification by stimulated emission of radiation.
The amount of asymmetry is controlled by the frequency detuning between the master and the freerunning slave lasers. Osa stability of periodone p1 oscillations generated. One of the characteristics of semiconductor lasers that is different from other lasers is the direct pump modulation. We present here theoretical and experimental evidence that other parameters may play a role. Theoretical analysis of optical injection locking in. However, the optical injection level is important in determining the dynamic. Thus, the cw optically injected laser has been used for testing methods either to suppress 7 or to generate on demand 8 high optical pulses. Strong optical injection locking of edgeemitting lasers and its applications by hyukkee sung doctor of philosophy in engineering electrical engineering and computer sciences university of california, berkeley professor ming c. Introduction strong optical injection locking of semiconductor lasers can provide an excellent transmitter for highspeed optical communication and a candidate for chaotic signals. Lau 1, xiaoxue zhao, hyukkee sung2, devang parekh, connie changhasnain 1, and ming c.
Injection locking in fabryperot cavity semiconductor lasers has been the subject of a large number of papers,11 but, although distributed feedback dfb lasers are among the most important industrial lasers used. Injection locking in fabryperot cavity semiconductor lasers has been the subject of a large number of papers,11 but, although distributed feedback dfb lasers are among the most important industrial lasers used in optical telecommunications, the theoretical study of injection locking in dfb lasers or more complex structure. Li l 1994b a unified description of semiconductor lasers with external light injection and its application to optical bistability. Locking and unlocking phenomena in optically injected semiconductor lasers have been extensively studied. We have experimentally demonstrated nearsingle sideband modulation in strong optical injectionlocked semiconductor lasers. Correlation properties and timeresolved dynamics of. Optically injected semiconductor lasers generate limitcycle dynamics of periodone and periodtwo oscillations. Lasers are used in optical disk drives, laser printers, barcode scanners, dna sequencing instruments, fiberoptic, semiconducting chip manufacturing photolithography, and freespace optical communication, laser surgery and skin treatments, cutting and welding materials, military and law enforcement devices for marking targets and measuring. Dynamical characteristics of an optically injected semiconductor laser. Alloptical frequency conversion using nonlinear dynamics. Semiconductor lasers subject to external optical injection have received a lot of attention, mainly due to applications such as injection locking 1, frewx quency stabilization 2 and chirp reduction 3.
It has been previously demonstrated that semiconductor lasers can be widely used in the chaotic optical communications as chaotic carrier sources, because of their ease of integration and generation of chaotic signals with additional perturbations, such as optical feedback, optical injection and optoelectronic feedback. Maiman at hughes research laboratories, based on theoretical work by charles. Smit2 1department of applied physics and photonics, vrije universiteit brussel, pleinlaan 2, 1050 brussels, belgium 2department of electrical engineering. Studies on the effective physical parameters forchirp. In semiconductor optical amplifiers soas, photons multiplied via stimulated emission. Optical injectionlocking oil as an applicable technique to modify the output characteristics of a semiconductor laser such as reducing the relative intensity noise and enhancing the side mode suppression ratio 22, 23 has also promising effects on modulation bandwidth and frequency chirp of semiconductor lasers. Driven by voltage, the doped pntransition allows for recombination of an electron with a hole. Nearsingle sideband modulation in strong optical injection. Dynamics in semiconductor lasers with optical injection. Demonstration of selfinjection locking of a fabryperot semiconductor laser operating at 690 nm. The resulting dynamics has been studied by measuring the output of the slave laser as the frequency detuning between the lasers, the injection strength, and the slave laser current are varied. Multipulse excitability in a semiconductor laser with optical injection. Dynamics and spectral characteristics of quantum dot.
Multilongitudinalmode dynamics in a semiconductor laser. The generation by optical injection locking of spectrally unadulterated microwave signals using waveguide based external cavity semiconductor lasers wecsl is demonstrated. Strong optical injection locked semiconductor laser for. Pdf although diode lasers are almost ideal sources for ultrahighspeed data. Indexing terms measurement, semiconductor lasers a simple and accurate method to measure the linewidth enhancement factor u in dfb semiconductor lasers is pro posed. This paper investigates sensitivity of semiconductor lasers to external optical signals. Photonics free fulltext optical sideband injection. Enhanced modulation characteristics of optical injection. A total of four singlemode semiconductor lasers are considered. By coupling the oi and the of lights into the same fiber before injecting into the slave laser sl, the ratio between the two perturbations can be accurately determined and controlled. A laser diode, ld, injection laser diode ild, or diode laser is a semiconductor device similar to a lightemitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diodes junction 3 laser diodes can directly convert electrical energy into light. Uchida, synchronization of bandwidth enhanced chaos in semiconductor lasers with optical feedback and injection. Among possible external perturbations to induce chaos in semiconductor lasers, external optical feedback has been frequently used to make chaotic lasers and the chaotic dynamics in such a system have been extensively studied. Exploiting the nonlinear dynamics of optically injected.
On phase noise of selfinjection locked semiconductor lasers. Synchronization of feedbackinduced chaos in semiconductor. Index termsinjectionlocked oscillators, microwave genera tion, nonlinear dynamics, optical injection, semiconductor lasers. Request pdf dynamical characteristics of an optically injected semiconductor laser the dependence of the dynamical characteristics of an optically injected. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Anticipating synchronization based on optical injection. Semiconductor lasers subjected to optical feedback from an external mirror or optical injection from another laser are known as nonlinear optical systems that can generate chaotic intensity. Analysis of an optically injected semiconductor laser for. Osa dynamical characteristics and their applications of.
Nonlinear dynamics of optically injected semiconductor lasers is interesting from a practical. Danckaert department of applied physics and photonics, vrije universiteit brussel. Strong optical injectionlocked semiconductor lasers. Injection locking, laser diode, optical communications, chaos 1. Pdf optical injection in semiconductor ring lasers. A tunable frequency of 211 ghz, limited by the modulators bandwidth and the photodetector pd, was created as proofofexperiment by the injection locking of the two wescls.
With the progress of optical transmission technology, various kinds of semiconductor lasers have been developed for the application to wavelength division multiplexing, high speed, low power consumption, and photonic integration. Open access correlated random bit generation using chaotic. Recently, optical injection locking has been proven to enhance the bandwidth and resonance frequency of directlymodulated semiconductor lasers. Up to 12db difference in upper and lower sideband power is observed. Narrow linewidth optical injection into a semiconductor laser can induce periodic oscillations in the injected laser s output power with a frequency that is widely tunable by simply varying the steadystate bias current and operating temperature. Strong optical injection locked semiconductor laser for high.
Multiscroll chaotic attractors in optical injected. For semiconductor lasers this frequency range contains the most figure 2 shows the tremendous reduction in the laser linewidths that can be achieved using this optical feedback locking method. The first relates to the semiconductor gain medium. Novel measurement technique of alpha factor in dfb. This method, based on the principle of external optical injection locking, does not require the knowledge of the absolute value of optical injection level. With unique advantages of broad frequency tuning range and large sideband rejection ratio, p1 oscillations can be useful in applications such as photonic microwave generation, radiooverfiber. The optical injection first drives the laser into p1 dynamics so that its intensity oscillates at a microwave frequency. The results show that onchip filtered optical feedback can be used to reduce the sensitivity of the semiconductor ring laser to external optical injection. Wu 1department of electrical engineering and computer sciences, university of california, berkeley. Semiconductor lasers with optical injection and feedback iopscience. Nonlinear dynamics of optically injected semiconductor lasers. Optical injection in semiconductor lasers has been shown to lead to a wealth of complex dynamics and bifurcations, such as periodone state, period doubling, quasiperiodicity, chaos, and injection locking 1. The first optical injection locking experiment, in 1966, used two hene lasers 29.
Thmdimensional model of a semiconductor laser consisting of three. A wide variety of nonlinear dynamical phenomena has aroused much interest in the. Strong optical injection locking of edgeemitting lasers. Wu, chair semiconductor lasers are essential components that enable highspeed longhaul. Chaos generation in a semiconductor ring laser with an. We now consider optical cavities in which the photons are confined in all three. The periodone p1 nonlinear dynamics of a semiconductor laser subject to both optical injection and optical feedback are investigated for photonic microwave generation. Three different complex laser structures are considered in detail. Spie 5452, semiconductor lasers and laser dynamics, 1 september 2004.