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Showing 1 to 20 of 21 for “"DFB-Laser"”.
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Oberflächengitter in azobenzenhaltigen Schichten für organische DFB-Laser
… werden organische Distributed Feedback-(DFB)-Laser zweiter Ordnung hergestellt, um den Einfluss von Gitterparametern auf die Emissionseigenschaften dieser Laser zu untersuchen. Dazu erfolgt zunächst die Charakterisierung der optischen Verstärkungseigenschaften ausgewählter organischer …
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Label-Free Biosensor Based Upon Replica-Molded Vertically Emitting Distributed Feedback Laser
The DFB laser sensor represents a departure from conventional passive resonant sensors insofar as the device actively generates its own narrowband high-intensity output without stringent requirements on the coupling alignments resulting in a simple, robust illumination and detection configuration. …
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From high power terahertz quantum cascade lasers to terahertz light amplifiers
… The invention of the THz quantum cascade laser, a electronically-pumped semiconductor heterostructure which emits photons from electronic intersubband transitions, provides the first solidstate fundamental oscillator at the frequency range from 1.2 to 5.1 THz. Due to the subwavelength …
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Abstimmbare Halbleiterlaser und schmalbandige Laserarrays mit verteilter lateraler Rückkopplung
… wurden zwei verschiedene Typen von Halbleiterlasern mit verteilter Rückkopplung (DFB-Laser) entwickelt. Die Laser basieren auf Rippenwellenleitern und verfügen zusätzlich über ein dazu senkrecht orientiertes Metallgitter. Der evaneszente Teil der im Rippenwellenleiter geführten Lichtwelle …
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Extensions of quartz-enhanced photoacoustic spectroscopy
… of NH3 in the 1.53 pm region with a DFB laser without the use of a resonating cavity. I analyzed the process of QEPAS both analytically and experimentally. First, absorption spectroscopy was performed with a 1.55 pm DFB laser on the 1558.033 nm absorption line of H13C12N. The …
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Label-free biosensor based upon a vertically emitting distributed feedback laser
… of solid state organic distributed feedback laser (DFB) biosensors. The combined techniques enable the organic DFB laser to be uniformly fabricated over large surface areas upon a flexible plastic substrate, with an approach that is compatible with roll-based manufacturing. Secondly, laser …
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Temperature and Spatial Hole Burning Effects in Semiconductor Lasers and Integrated Optical Devices
… are investigated in long-wavelength InP-based lasers and integrated optical devices, including Fabry-Perot (FP) lasers, distributed-feedback (DFB) lasers, and integrated electroabsorption modulator with DFB lasers (EML). First, the temperature dependence of bulk InGaAsP semiconductor laser …
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Synthesis, design and characterization of a distributed feedback grating based non-linear optical chemosensor
… focused our efforts is the Distributed Feedback (DFB) laser cavity. The waveguide materials synthesized are Si and Ti inorganic matrices that were optimized for optical waveguiding by determining the appropriate film thickness, refractive index and film smoothness. Amplified stimulated emission …
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UV-written devices in rare-earth doped silica-on-silicon grown by FHD
… demonstration of an all-UV-written waveguide laser in silica-on-silicon. Low-loss operation (0.11-0.3 dBcm<sup>-1</sup>) of a 10mm long channel waveguide laser doped with 1.26wt% of neodymium was demonstrated with efficient lasing action (~ 33% slope efficiency). <br/><br/>Erbium, ytterbium …
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Development of high power fibre amplifier components, systems and applications
… a fibre-in beam-out isolator for use with fibre lasers. The first project developed a fibre Raman amplifier which amplified a 10mW narrow linewidth DFB laser at 1651nm to an output power of over 2W. To achieve this high output power from a narrow linewidth Raman amplifier mechanisms to suppress …
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The development of components for ultrafast all-optical communication networks
… (WDM) propagation is the distributed feedback (DFB) laser. A periodic index modulation, typically buried within the device structure (hence requiring an overgrowth step), is used to select the specific operating wavelength of the laser. As the WDM wavelength spacing continues to decrease, the …
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Fiber Bragg Gratings Strain Sensors for Railway Applications
… sensor system with a distributed feedback (DFB) laser as the light source has been implemented. We show that it has superior noise and sensitivity performances compared to strain gauge sensors. The design has been extended to accommodate multiple sensors with negligible cross talk. When two …
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Ultrashort pulse generation from diode laser devices
… of ultrashort optical pulses from diode lasers. Simple and cost-effective techniques were used to generate high power, high quality optical short pulses at various wavelength windows. The major achievements presented in the thesis is summarised as follows. High power pulses generation is …
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Herstellung und Charakterisierung von kanten- und vertikalemittierenden (Ga)InAs/Ga(In)As-Quantenpunkt(laser)strukturen
Im Vergleich zu Quantenfilmlasern haben Quantenpunktlaser (unter anderem) die Vorteile, dass kleinere Schwellenströme zu erreichen sind und die Emissionswellenlänge über einen größeren Bereich abgestimmt werden kann, da diese aufgrund der Größenfluktuation im Quantenpunktensemble über ein breites …
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Ultra-long haul optical fibre transmission systems
… are enhanced by the use of a directly modulated DFB laser transmitter and total insensitivity of the system to the signal state of polarisation. Optically amplified ultra-long haul NRZ systems have taken on particular importance with the impending deployment of TAT 12/13 and TPC 5. The …
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All-semiconductor High Power Mode-locked Laser System
… gain-coupled distributed-feedback (MS-GC DFB) lasers are discussed. A record speed of 180-GHz timing synchronization has been demonstrated using this device. An all-optical carrier synchronization (phase and polarization recovery) scheme from PSK (phase shift keying) data is proposed and …
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Organic semiconductor lasers with two-dimensional distributed feedback
… a comprehensive investigation of solid-state lasers based on thin films of a disordered organic semiconductors (OS). The high luminescence yield of OS together with their conductivity and the ease of processing them into sub-micron thick films on substrates of virtually any shape and size open …
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Advances in tunable diode laser spectroscopy for aero engine research
Tunable diode laser spectroscopy (TDLS) is a widely used technique for the measurement of gas species and offers in-situ operation, accuracy and faster response time compared to other optical and non-optical gas sensing techniques.The work in this thesis focusses on the measurement of CO2 in the …
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Polarization multiplexed photonic integrated circuits for 100 Gbit/s and beyond
… out in a serial configuration. Furthermore, a laser source is monolithically integrated. All devices are realized in the semiconducting material system of indium phosphide (InP) and its related quaternary alloys (InGaAsP). The technology used for fabrication is referred to as generic, meaning …
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Investigation and development of a novel metrology standard for the measurement of relative intensity noise and frequency chirp of DFB lasers in optical networks
Laser diode Relative Intensity Noise (RIN) metrology capabilities have been developed and demonstrated, providing significantly improved sensitivity and accuracy than existing methods. This is a key parameter for laser components used in telecommunication systems due to the drive to reduce inherent …
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