Nós estudamos experimentalmente e teoricamente Efeitos Transientes em conjugação de Fase por Mistura Degenerada de Quatro ondas em cristais dopados com Cr POT. 3+. Estudamos os efeitos transientes na conjugação de fase em Al IND 2 O IND. 2 : Cr POT. 3+ (Rubi) e GdAl O IND. 3 Cr POT. 3+ (aluminato de gadolíneo) com um laser de Ar POT. + (em =514,5nm). Um novo modelo teórico é apresentado que explica razoavelmente os resultados experimentais cuja compreensão anterior pela literatura era devido somente pela parte absortiva do índice de refração[12] pois em cristais dopados com Cr POT. 3+ (Al IND. 2 O IND. 3: Cr POT. 3+ e GdAl O IND. 3 : Cr POT. 3+ a parte dispersiva do índice de refração não-linear n IND. 2 é pelo menos uma ordem de grandeza maior que a parte absortiva [15,28]. / We have studied experimentally and theoretically Transient Effects in Degenerate Four-Wave Mixing by Phase Conjugation in ion-doped crystals with Cf3+. We have studied transient effects in phase conjugation in Al2O3:Cf3+ (Ruby) and GdAlO3:Cr3+ Gadolinium Aluminate) with an Argon laser (at =514.5nm). A new theoretical model is presented that reasonably explains our experimental results whose understanding in previous papers was due to the imaginary part of the refraction index [12] because in crystals doped with cr3+ (Al2O3:Cr3+ and GdAIO3:Cr3+) the real part of the nonlinear refraction index n2 is at least one order of magnitude greater than the imaginary part [15,28].

For packet-switched metro networks, one of the key functional blocks is the transmission, extraction and update of in-band packet control information, which is commonly known as packet label swapping. The use of phase modulation to carry the control information can facilitate easy swapping process. By combining phase modulated label with intensity modulated optical packets in non-overlapping manners, we demonstrated that optical packet label swapping using differential phase-shift keyed labels could be achieved without any sacrifices in packet signal quality. / In packet-switched optical networks, packets are routed using IP-based distributed routing algorithms. Inconsistencies in routing information among routing nodes may result in routing loop formation in the network and may cause severe impact on the network performance. We proposed a novel packet routing loop mitigation scheme based on the principle of packet 'time-to-live' value countdown. This scheme enables loop mitigation to be performed asynchronously in optical domain, causing little packet processing delay. Two implementations were proposed. One was based on differential optical phase shift keying and the other was based on self-phase modulation in semiconductor optical amplifier. / The continuous increase in Internet-bound data traffic in recent years has placed higher requirement on network bandwidth and flexibility. In view of this, packet-switched metro networks and broadband passive optical access networks have emerged as the promising network solutions in the near future. The focus of this thesis is on the improvement of functionality and reliability as well as the reduction of system complexity in optical metro area and access networks with the use of optical phase modulation techniques. In access network, constant-intensity optical phase modulation formats were studied for their applications in wavelength-division-multiplexed passive optical networks with centralized light source. Using them as downstream modulation formats, the downstream optical carrier can be utilized to carry upstream intensity-modulated data. It can greatly simplify upstream transmission and facilitate network management. Experimental and numerical analyses shows promising upstream re-modulation performance with a simple optical network unit (ONU) configuration. / Hung Wai. / Adviser: Lian-Kuan Chen. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 130-135). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

by Tong Wai Yin Alex. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaf 55). / by Tong Wai Yin Alex. / Acknowledgement / Biographical Sketch / Abstract / Table of contents / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Nonlinear Optics in dye-doped solid --- p.4 / Chapter 2.1 --- Nonlinear Optics --- p.4 / Chapter 2.2 --- Photophysics of dye molecules --- p.6 / Chapter 2.3 --- Nonlinear effect in dye-doped solid --- p.8 / Chapter Chapter 3 --- Sol-Gel Silica --- p.11 / Chapter 3.1 --- The formation of dye-doped sol-gel silica --- p.11 / Chapter 3.2 --- The physical properties --- p.15 / Chapter 3.3 --- The optical properties --- p.16 / Chapter Chapter 4 --- Saturation Absorption --- p.18 / Chapter 4.1 --- Saturation Absorption in Fluorescein 548 dye-doped solid --- p.18 / Chapter 4.2 --- Experimental Details --- p.19 / Chapter 4.3 --- Results and Discussion --- p.19 / Chapter 4.4 --- Conclusion --- p.30 / Chapter Chapter 5 --- Optical Phase Conjucation --- p.31 / Chapter 5.1 --- OPC Theory --- p.31 / Chapter 5.11 --- The Distortion Correction Theorem --- p.32 / Chapter 5.12 --- The Proof of the Distortion Theorem --- p.32 / Chapter 5.13 --- The generation of Phase Conjucate Waves --- p.34 / Chapter 5.2 --- Degenerate Four Wave Mixing --- p.35 / Chapter 5.21 --- Geometries of DFWM --- p.35 / Chapter 5.22 --- DFWM Theory --- p.37 / Chapter 5.23 --- DFWM in Absorbing Media --- p.40 / Chapter 5.3 --- Experimental Details --- p.44 / Chapter 5.4 --- Results and Discussion --- p.46 / Chapter 5.5 --- Conclusion --- p.53 / Chapter Chapter 6 --- Conclusion and Suggestions for future work --- p.54 / Reference

Nós estudamos experimentalmente e teoricamente Efeitos Transientes em conjugação de Fase por Mistura Degenerada de Quatro ondas em cristais dopados com Cr POT. 3+. Estudamos os efeitos transientes na conjugação de fase em Al IND 2 O IND. 2 : Cr POT. 3+ (Rubi) e GdAl O IND. 3 Cr POT. 3+ (aluminato de gadolíneo) com um laser de Ar POT. + (em =514,5nm). Um novo modelo teórico é apresentado que explica razoavelmente os resultados experimentais cuja compreensão anterior pela literatura era devido somente pela parte absortiva do índice de refração[12] pois em cristais dopados com Cr POT. 3+ (Al IND. 2 O IND. 3: Cr POT. 3+ e GdAl O IND. 3 : Cr POT. 3+ a parte dispersiva do índice de refração não-linear n IND. 2 é pelo menos uma ordem de grandeza maior que a parte absortiva [15,28]. / We have studied experimentally and theoretically Transient Effects in Degenerate Four-Wave Mixing by Phase Conjugation in ion-doped crystals with Cf3+. We have studied transient effects in phase conjugation in Al2O3:Cf3+ (Ruby) and GdAlO3:Cr3+ Gadolinium Aluminate) with an Argon laser (at =514.5nm). A new theoretical model is presented that reasonably explains our experimental results whose understanding in previous papers was due to the imaginary part of the refraction index [12] because in crystals doped with cr3+ (Al2O3:Cr3+ and GdAIO3:Cr3+) the real part of the nonlinear refraction index n2 is at least one order of magnitude greater than the imaginary part [15,28].

This thesis proposes a novel technique using a phase-lock loop (PLL) style phase control loop to achieve retrodirective phased array antenna steering. This novel approach introduces the concept of phase scaling and frequency translation. It releases the retrodirective transmit-receive frequency ratio from integer constraints and avoids steering approximation errors. The concept was developed to achieve automatic and precise beam steering for the solar power satellite (SPS). The testing was performed using a transceiver converting a pair of received 2.9 GHz signals down to 10 MHz, and up converting two 10 MHz signals to 5.8 GHz. Phase scaling and conjugation was performed at the 10 MHz IF using linear XOR phase detectors and a PLL loop to synthesize a 10 MHz signal with conjugate phase. A phase control loop design is presented using PLL design theory achieving a full 2π steering range. The concept of retrodirective beam steering is also presented in detail. Operational theory and techniques of the proposed method are presented. The prototype circuit is built and the fabrication details are presented. Measured performance is presented along with measurement techniques. Pilot phase detectors and PCL achieve good linearity as required. The achieved performance is benchmarked with standards derived from likely performance requirements of the SPS and beam steering of small versus large arrays are considered.

Virtual aperture culling of the eigenmodes of a resonator (VACER) is a technique to focus light within turbid media at arbitrary locations. A seed pulse of light is directed through a phase-conjugate mirror (PCM) into a turbid medium. Though much of the light may be lost, any light which reaches the second PCM is phase conjugated and thus returned to the first PCM where the light will be phase conjugated again. Amplification by the PCMs can prevent decay of the light cycling between the PCMs. Introducing a mechanism which filters light based on position enables attenuation of the modes not traveling through the center of the virtual aperture resulting in a focusing of light at the center of the virtual aperture. The seed pulse and the positioning of the PCMs on opposite sides of the virtual aperture ensure that modes cannot bypass the virtual aperture. Magnetic fields and ultrasound waves are potential means for implementation of a virtual aperture. Generally, only weak filtration mechanisms like magnetic fields and ultrasound waves are innocuous to turbid media. Fortunately, weak effects can strongly cull modes in VACER because the filtration mechanism affects the modes during each pass between PCMs and the modes compete. A combination of theory and computational modeling prove that sound physical principles underlie VACER. Moreover, computational modeling reveals how mode overlap, the seed pulse, and other variables impact VACER performance. Good experimental performance is predicted. / text

Der photorefraktive Effekt in Bariumtitanat-Kristallen ist Gegenstand zahlreicher Forschungsarbeiten. Der Grund sind die großen elektrooptischen Koeffizienten dieses Materials, die nur von wenigen, kommerziell noch nicht erhältlichen Kristallen übertroffen werden, z.B. von tetragonalem Kalium-Tantalat-Niobat. Beleuchtet man diese Materialien mit Laserstrahlen, treten einzigartige Effekte auf. So erzeugen z.B. photorefraktive parametrische Verstärkungsprozesse charakteristische kreis- oder linienförmige Streulichtfiguren. Faszinierende Möglichkeiten bieten diese parametrischen Prozesse bei der Verstärkung und Phasenkonjugation von Lichtwellen. In dieser Arbeit werden alle 57 photorefraktiven parametrischen Prozesse, die in den untersuchten Materialien auftreten können, zunächst phänomenologisch analysiert. Das Lösen der gekoppelten Wellengleichungen filtert aus der Vielzahl der Prozesse diejenigen heraus, die eine besonders effiziente Wechselwirkung einfallender Lichtwellen versprechen. Für diese Prozesse werden anschließend explizit Verstärkungsfaktoren berechnet. Durch die Berücksichtigung elastooptischer, piezoelektrischer und raumladungsbegrenzender Effekte können die Einfallswinkel der Lichtstrahlen und die Orientierungen der Kristalle für die Signalstrahlverstärkung und die Phasenkonjugation optimiert werden. Auf der Basis dieser theoretischen Vorarbeiten gelingt im experimentellen Teil dieser Arbeit zum ersten Mal die Verstärkung eines Laserstrahls durch einen photorefraktiven parametrischen Prozeß. Die Verstärkung beträgt in einem 3,2 Millimeter dicken Bariumtitanat-Kristall 9000. Eine Besonderheit der angewandten Verstärkungsprozesse ist die sehr geringe räumliche Bandbreite. Die daraus folgende große Winkelselektivität verspricht viele Anwendungsmöglichkeiten in der optischen Meßtechnik, schränkt den Einsatz zur Bildverstärkung jedoch erheblich ein. Ebenfalls zum ersten Mal wird die Phasenkonjugation durch einen phototrefraktiven parametrischen Prozeß demonstriert. Die Intensitäten der erzeugten phasenkonjugierten Wellen entsprechen denen der verstärkten Signalstrahlen. Es lassen sich also Reflektivitäten bis zu 9000 realisieren. Zudem kann durch eine spezielle Konfiguration mit frequenzverstimmten Signalstrahlen ein prinzipielles Problem der photorefraktiven Wellenmischung gelöst werden: Die Verstärkung sehr schwacher Signalstrahlen. Durch die neu entwickelte Methode der Rauschunterdrückung gelingt es, Lichtwellen mit Leistungen unter einem Nanowatt um mehrere Größenordnungen zu verstärken. Zum Abschluß werden die parametrischen Prozesse noch in Kalium-Tantalat-Niobat untersucht. Bei diesen ersten Untersuchungen gelingt der Nachweis von fünf Prozessen. Die beobachteten ausgeprägten Effekte und die gemessenen riesigen elektrooptischen Koeffizienten zeigen, daß tetragonale Kalium-Tantalat-Niobat-Kristalle ebenfalls sehr interessant für die photorefraktive Wellenmischung sind.

Cet ouvrage présente de nouveaux aspects de l’analogie entre temps et espace pour les ondes, à travers des concepts de contrôle temporel de la propagation des ondes, qui peuvent être interprétés comme la transposition au domaine temporel d’opérations standard du domaine spatial. Toute l’étendue de cette analogie est étudiée dans le cadre deux phénomènes ondulatoires bien connus (dans leurs versions spatiales), et dont nous montrons qu’ils sont étroitement liés : la réflexion des ondes et leur transformation par un cristal. En particulier, il est démontré expérimentalement que l’analogue temporel de la réflexion par un miroir génère une onde retournée temporellement, c’est-à-dire dont l’évolution temporelle est inversée. Une variante monofréquentielle de ce miroir temporel instantané, qui possède des liens étroits avec le concept de conjugaison de phase utilisé pour le retournement temporel d'ondes monochromatiques en optique, est également étudiée. Nous montrons que la modulation temporelle périodique du milieu mise en jeu dans ces expériences constitue l'équivalent temporel d'un cristal pour les ondes et étudions les propriétés générales des ondes dans ces milieux. Nous cherchons naturellement à sonder les limites de ces analogies spatiotemporelles, dont, de toute évidence, le principe de causalité est un élément majeur. Les phénomènes étudiés sont généraux et communs à toutes les ondes classiques, gouvernées en général par l’équation de d’Alembert ou par d’autres équations similaires. Les ondes à la surface d’un liquide sont utilisées comme système ondulatoire modèle dans nos expériences / This work presents new aspects of the analogy between time and space in wave phenomena, through new concepts of time control of wave propagation which can be interpreted as the transposition onto the time domain of standard spatial operations. The depth of this analogy is thoroughly studied in the framework of two well-known wave phenomena: reflection of waves on a mirror and their transformation by a crystal. More precisely, we experimentally demonstrate that the time analog of reflection by a mirror generates a time reverse wave that is whose time evolution is inverted. A monofrequency variant of this instantaneous time mirror, which has strong connections to the concept of wave phase conjugation used for time reversing monochromatic waves in optics, is also studied. We show that the periodic time modulation of the medium involved in the latter experiments constitutes the time equivalent of a crystal for waves and we study the general properties of waves in such media. We address of course the issue of the limits of theses space time analogies, of which, the principle of causality is evidently a major constituent. The phenomena studied here are general and apply to all classical waves (usually governed by d’Alembert’s equation or by similar ones). Waves at the surface of a liquid are used as a model wave system in our experiments / Die Universalitat der klassischen Wellenphanomenen lasst sich weitgehend durch die d’Alembertsche Struktur der Wellengleichungen beschreiben. In letzterer spielen die Zeit- und Raumvariabeln eine ahnliche Rolle. Wir betrachten in diesem Werk diese bekannte Analogie unter einem neuen Licht, indem wir neue Konzepte der Zeitkontrolle von der Wellenpropagation introduzieren, die als Transposition zum Bereich der Zeit von standarden Wellenphanomen des Raumes interpretiert werden konnen, wobei die raumliche Variation der Eigenschaften des Mediums, die sie bestimmen, durch eine zeitliche ersetzt wird. Wir bringen den experimentellen Beweis der Relevanz dieses Ansatzes, wobei wir die Wellen an der Oberflache einer Flussigkeit als Modelwellensystem verwenden und zeigen durch theoretische Erkenntnisse, dass er auf alle Wellensysteme generalisiert werden kann, die durch eine Wellengleichung beschrieben wird, deren 10 Struktur die der d’Alembertschen Gleichung ahnelt. Die ganze Reichweite dieser Analogie wird im Rahmen zweier langst bekannten Wellenphanomenen (in deren raumlichen Version), von denen wir zeigen, dass sie eng verbunden sind : die Spiegelung einer Welle und deren Umwandlung durch einen Kristal. Das Equivalent eines Spiegels fuhrt zur augenblicklichen Erscheinung aus dem gesammten Raum einer zeitumgekehrten Welle, das heist einer Wellenform, derer zeitliche Entwicklung im Vergleich zu der originellen Welle umgekehrt ist. Eine Einzelfrequenzvariante dieses augenblicklichen Zeitspiegels wird auch vorgestellt, die enge Verbindungen mit dem fur die Zeitumkehr monochromatischer Wellen angewendeten Konzept der optischen "Phase Conjugation" (Phasenkonjugierung) besitzt. Wir zeigen, dass die dazugehorige periodische Zeitmodulation des Mediums das zeitliche Equivalent eines Kristals fur die Welle bildet, und wir studieren die generellen Eigenschaften der Wellen in solchen Medien. Wir versuchen, die Grenzen dieser raumzeitlichen Analogien zu erkundigen, in derer Bestimmung selbstverstandlich das Kausalitatsprinzip eine masgebliche Rolle spielt, und die interessanten Unterschiede zwischen den vorgestellten Konzepten und deren raumlichen Pendants offenbaren / La universalidad de los fenomenos ondulatorios clasicos es ampliamente descrita por la estructura de la ecuacion de d’Alembert. En esta ecuacion, las variables espaciales y temporales desempenan un papel similar. En esa obra, revisitamos esta analogia bien conocida a traves de nuevos conceptos de control temporal de la propagacion de las ondas, quienes pueden ser interpretados como transposiciones de fenomenos espaciales estandartes al ambito temporal, en los cuales las variaciones espaciales de las propiedades del medio son reemplazadas por las correspondientes variaciones temporales. Hacemos la prueba, usando ondas a la superficie de un liquido, de la relevancia de este enfoque y mostramos teoreticamente su generalizacion a todo tipo de onda clasica, es decir gobernada por una ecuacion cuya estructura es similar a la de d’Alembert. Toda la extension de esta analogia queda estudiada en el cuadro de los dos fenomenos clasicos (en sus versiones espaciales) que son la reflexion de una onda sobre un espejo y su trasformacion en un cristal. Ademas, mostramos que los dos son intimamente relacionados. El equivalente temporal de un espejo produje instantaneamente desde el medio entero una onda retornada en el tiempo, es decir cuya evolucion temporal es invertida comparado a la onda inicial. Una variante monofrecuencial de este espejo queda estudiada tambien. Posee estrechos vinculos con el concepto de Phase Conjugation (conjugacion de fase), usado en Optica para hacer retornamiento temporal de ondas monocromaticas. Mostramos que la modulacion temporal implicada constituye el equivalente de un cristal para las ondas et estudiamos las caracteristicas generales de ondas en estos medios. Sondeamos los limites de esas analogias espaciotemporales de cuyos obviamente el principio de causalidad es un elemento mayor y que revelan diferencias interesantes entre los conceptos presentados y sus equivalentes espaciales / L’universalita dei fenomeni ondulatori classici e in larga misura descritta dalla struttura dell’equazione di d’Alembert. In quest’equazione, le variabili spaziali e temporali svolgono ruoli analoghi. Nell’opera seguente rivisitiamo questa ben nota analogia introducendo nuovi concetti sul controllo temporale della propagazione delle onde. Questi concetti possono essere interpretati come trasposizione di fenomeni ondulatori spaziali standard nell’ambito temporale, sostituendo le variazioni spaziali delle proprieta del mezzo con le variazioni temporali corrispondenti. Usando delle onde sulla superficie di un liquido come modello fisico, facciamo fede della rilevanza di quell’approccio e mostriamo teoricamente la generalizzazione a tutti i tipi di onde classiche, governate da equazioni simili a quella di d’Alembert. Questa analogia viene studiata nell’ambito di due fenomeni ondulatori ben noti (nella loro versione spaziale) : la riflessione delle onde generata da un specchio e la loro trasformazione generata da un cristallo. Mostriamo inoltre che i due concetti sono intimamente vincolati. L’equivalente temporale di un specchio porta alla generazione in tutto lo spazio di un’onda restituita nel tempo, vale a dire un’onda di cui l’evoluzione temporale e invertita in relazione all’onda originale. In questa tesi viene presentata anche una variante monofrequenziale di questo specchio temporale istantaneo che possiede legami stretti con il concetto di coniugazione di fase usato in ottica per invertire nel tempo onde monocromatiche. Mostriamo in questo lavoro che la modulazione temporale periodica del mezzo in questione costituisce, per le onde, l’equivalente temporale di un cristallo e ne studiamo le proprieta generali. In questa tesi, cerchiamo di sondare i limiti dell’analogia spaziotemporale, di cui il principio di causalita ne e l’essenziale e che rivelano differenze interessanti tra i concetti presentati e i loro equivalenti spaziali

This thesis is a theoretical and experimental study of the dynamics of an edge-emitting laser diode (850 nm) with phase-conjugate feedback. The experimental device is designed to see the dynamical range of the laser through the temporal and spectral properties while the feedback rate varies. Phase-conjugate feedback is performed through four-wave mixing in a photorefractive crystal. The propagation time of the laser beam in the external cavity is termed external time delay. Under the effect of the feedback, the system shows a wide dynamical range including chaos and self-pulsing states which characteristic properties are determined by the length of the external cavity. For the first time self-pulsing states at frequencies multiples of the fundamental frequency of the external cavity are evidenced. Simulations carried out based on the commonly-used Lang-Kobayashi laser rate equations provide theoretical confirmations to the experimental observations. The main topics tackled here are chaos crisis and bistability of pulsing solutions, self-pulsing regimes (through their stabilization and destabilization) and the transitions between them, characterization of extreme events of two kinds along with their statistical distribution and delay-induced deterministic coherence resonance of low frequency fluctuations. Beyond the fundamental interest of these results and the many comparisons that can be made with other laser systems, applications in the field of all-optical signal generation and control of chaos are direct consequences of this study.

Cette thèse consiste en une étude théorique et expérimentale de la dynamique d'une diode laser à émission latérale (850 nm) avec rétroaction optique à conjugaison de phase. Le dispositif expérimental est conçu afin de voir la diversité dynamique du laser à travers l'analyse temporelle et spectrale alors que le taux de rétroaction varie. La rétroaction à conjugaison de phase est effectuée par mélange à quatre ondes dans un cristal photoréfractif. Le temps de propagation du faisceau laser dans la cavité externe est appelé retard. Sous l’effet de la rétroaction, le système montre une grande richesse dynamique qui varie du chaos total à des régimes auto-pulsés aux fréquences déterminés par le longueur de la cavité externe pour la première fois mis en évidence ici. Des simulations menées en parallèle basées sur les équations de Lang-Kobayashi couramment utilisées apportent des confirmations théoriques aux observations expérimentales. Les principaux points traités sont la crise chaotique et bistabilité de solutions pulsées, les régimes auto-pulsés (stabilisation et déstabilisation) ainsi que les transitions entre eux, la caractérisation d’événements extrêmes de différentes natures avec la distribution statistique associée ainsi qu’une résonance cohérente déterministe de fluctuations à basse fréquence induite par le retard. Au-delà de l’intérêt fondamental de ces résultats et des comparaisons qui peuvent être établies avec d’autres systèmes laser, des applications dans la génération de signaux tout-optique ainsi que le contrôle du chaos sont des débouchés potentiels de cette étude. / This thesis is a theoretical and experimental study of the dynamics of an edge-emitting laser diode (850 nm) with phase-conjugate feedback. The experimental device is designed to see the dynamical range of the laser through the temporal and spectral properties while the feedback rate varies. Phase-conjugate feedback is performed through four-wave mixing in a photorefractive crystal. The propagation time of the laser beam in the external cavity is termed external time delay. Under the effect of the feedback, the system shows a wide dynamical range including chaos and self-pulsing states which characteristic properties are determined by the length of the external cavity. For the first time self-pulsing states at frequencies multiples of the fundamental frequency of the external cavity are evidenced. Simulations carried out based on the commonly-used Lang-Kobayashi laser rate equations provide theoretical confirmations to the experimental observations. The main topics tackled here are chaos crisis and bistability of pulsing solutions, self-pulsing regimes (through their stabilization and destabilization) and the transitions between them, characterization of extreme events of two kinds along with their statistical distribution and delay-induced deterministic coherence resonance of low frequency fluctuations. Beyond the fundamental interest of these results and the many comparisons that can be made with other laser systems, applications in the field of all-optical signal generation and control of chaos are direct consequences of this study.