The first modelocked Er: Ti: LiNbO3-waveguide laser with intracavity phase modulator as the mode locker is reported. The laser was pumped at lambda(p) congruent-to 1480 nm, (E(p) parallel-to c) and the phase modulator...
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The first modelocked Er: Ti: LiNbO3-waveguide laser with intracavity phase modulator as the mode locker is reported. The laser was pumped at lambda(p) congruent-to 1480 nm, (E(p) parallel-to c) and the phase modulator was driven sinusoidally at 1.441 GHz (axial mode spacing of the 48 mm long cavity). Modelocked pulses at lambda(s) congruent-to 1532 nm (pi-polarised) with more than 1.5 mW peak power were generated. The observed pulse width (95 ps FWHM) at 1.6 times the threshold pump power (approximately 40 mW coupled) and 30.5 dBm RF-drive power were limited by the detector bandwidth (approximately 6 GHz).
A finite-difference beam-propagation method is derived directly from the vectorial Maxwell equations. The new approach allows the analysis of coupling between various components of the electric-field vector for optica...
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A finite-difference beam-propagation method is derived directly from the vectorial Maxwell equations. The new approach allows the analysis of coupling between various components of the electric-field vector for optical beam propagating in dielectric waveguides as well as corresponding changes in the beam-polarisation state.
One of the major advantages of Raman lasers is their ability to generate coherent light in wavelength regions that are not easily accessible with other conventional types of lasers(1). Recently, efficient Raman lasing...
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One of the major advantages of Raman lasers is their ability to generate coherent light in wavelength regions that are not easily accessible with other conventional types of lasers(1). Recently, efficient Raman lasing in silicon in the near- infrared region has been demonstrated(2-4), showing great potential for realizing low- cost, compact, room- temperature lasers in the mid- infrared region(5-7). Such lasers are highly desirable for many applications, ranging from trace- gas sensing, environmental monitoring and biomedical analysis, to industrial process control, and free- space communications(8,9). Here we report the first experimental demonstration of cascaded Raman lasing in silicon, opening the path to extending the lasing wavelength from the near- to midinfrared region. Using a 1,550- nm pump source, we achieve stable, continuous- wave, second- order cascaded lasing at 1,848 nm with an output power exceeding 5 mW. The laser operates in single mode, and the laser linewidth is measured to be < 2.5 MHz.
We show that optically induced photonic lattices in a nonconventionally biased photorefractive crystal can support the formation of discrete and gap solitons owing to a mechanism that differs from the conventional scr...
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We show that optically induced photonic lattices in a nonconventionally biased photorefractive crystal can support the formation of discrete and gap solitons owing to a mechanism that differs from the conventional screening effect. Both the bias direction and the lattice orientation can dramatically influence the nonlinear beam-propagation dynamics. We demonstrate a transition from self-focusing to -defocusing and from discrete to gap solitons solely by adjusting the optical-beam orientation. (C) 2008 Optical Society of America.
A novel and unique application of leaky waveguides as feeding systems for microwave planar antennas is presented. A new leaky nonradiative dielectric (NRD) guide based on a grating structure is proposed, and a planar ...
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A novel and unique application of leaky waveguides as feeding systems for microwave planar antennas is presented. A new leaky nonradiative dielectric (NRD) guide based on a grating structure is proposed, and a planar array slot antenna using this leaky waveguide is constructed and measured at 23 GHz.
A low-cost multimode optical fiber based sensor has been reported for measuring the refractive index (RI) of liquid samples. In this sensor, a light is coupled from a multimode optical fiber to a customized U-shaped g...
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A low-cost multimode optical fiber based sensor has been reported for measuring the refractive index (RI) of liquid samples. In this sensor, a light is coupled from a multimode optical fiber to a customized U-shaped glass tube, and light emerging out of the U-shaped glass tube is guided onto a photodetector with the help of another multimode fiber. The intensity of light detected by the photodetector is found to vary with the RI of liquid sample that comes into contact with the U-shaped glass tube. A sensor response has also been observed by changing the bending radius of the glass tube and the depth of surrounding liquid medium. The proposed sensor is expected to be more rugged and reliable, as compared to a tapered optical fiber and the U-shaped optical fiber refractometers.
A Yb-doped silica microcavity laser on a silicon chip is fabricated from a solgel thin film. The high-Q microtoroid cavity, which has a finesse of 10,000, is evanescently coupled to an optical fiber taper. We report a...
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A Yb-doped silica microcavity laser on a silicon chip is fabricated from a solgel thin film. The high-Q microtoroid cavity, which has a finesse of 10,000, is evanescently coupled to an optical fiber taper. We report a threshold of 1.8 mu W absorbed power that is, to the best of our knowledge, the lowest published threshold to date for any Yb-doped laser. The effect of Yb3+ Concentration on laser threshold is experimentally quantified. (c) 2007 Optical Society of America.
The process of bonding InP/InGaAsP dies to a processed silicon-on-insulator wafer using sub-300 nm layers of DVS-bis-benzocyclobutene (BCB) was developed. The planarization properties of these DVS-bis-BCB layers were ...
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The process of bonding InP/InGaAsP dies to a processed silicon-on-insulator wafer using sub-300 nm layers of DVS-bis-benzocyclobutene (BCB) was developed. The planarization properties of these DVS-bis-BCB layers were measured and an optimal prebonding die preparation and polymer precure are presented. Bonding quality and bonding strength are assessed, showing high-quality bonding with sufficient bonding strength to survive postbonding processing. (c) 2006 The Electrochemical Society.
Three-dimensional photonic waveguide devices are fabricated in glass by use of femtosecond pulses from an extended-cavity laser oscillator. Three-dimensional devices, including a symmetric three-waveguide directional ...
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Three-dimensional photonic waveguide devices are fabricated in glass by use of femtosecond pulses from an extended-cavity laser oscillator. Three-dimensional devices, including a symmetric three-waveguide directional coupler and a three-dimensional microring resonator, are fabricated and tested. waveguides can be fabricated at depths of -1 mm inside a glass substrate, thus demonstrating the capability of achieving dramatic increases in device density. These results demonstrate the potential to fabricate new classes of devices that are not possible in two dimensions. (c) 2005 Optical Society of America.
It is shown that electromagnetic energy can be localized to defect regions bounded by parallel planar walls perpendicular to the stack surface in Bragg stacks of two-dimensional photonic crystals. These regions produc...
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It is shown that electromagnetic energy can be localized to defect regions bounded by parallel planar walls perpendicular to the stack surface in Bragg stacks of two-dimensional photonic crystals. These regions produce larger bandgaps than single-photonie-crystal slabs. Group velocity and dispersion relations can easily be tailored by choice of the proper geometry and materials. Results indicate that such photonic crystals might facilitate photonic trapping and storage together with advanced photonic manipulations. (C) 2004 Optical Society of America
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