The authors numerically investigate optical bistability in a periodic waveguide in the presence of a quadratic nonlinearity allowing phase-matched second-harmonic generation. The structure is a tuned Bragg coupler for...
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The authors numerically investigate optical bistability in a periodic waveguide in the presence of a quadratic nonlinearity allowing phase-matched second-harmonic generation. The structure is a tuned Bragg coupler for two counterpropagating modes al the fundamental frequency, and is coherently controlled by a seed at the second harmonic.
All-optical refractive nonlinearity in a passive InGaAs/InAlAs multiquantum well waveguide is evaluated for TE and TM modes at 1.55 mum wavelength and room temperature. A quarter wavelength change in the optical path ...
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All-optical refractive nonlinearity in a passive InGaAs/InAlAs multiquantum well waveguide is evaluated for TE and TM modes at 1.55 mum wavelength and room temperature. A quarter wavelength change in the optical path length is observed at an input pump light power of 6.5 mW for 1.47 mum wavelength in a 960 mum long device. Nonlinear refractive index n2 is evaluated to be -1.2x10(-6) and -0.5x10(-6)cm2/W for the TE and the TM modes, respectively.
The authors report the simple integration of a 1.55mum optical amplifier taper with a coupling waveguide yielding a lateral beam divergence of 7.5-degrees, a lateral spot size expansion factor of 9.5 and a coupling lo...
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The authors report the simple integration of a 1.55mum optical amplifier taper with a coupling waveguide yielding a lateral beam divergence of 7.5-degrees, a lateral spot size expansion factor of 9.5 and a coupling loss to a cleaved standard fibre of 2.6dB.
A polarisation independent all-optical modulator is presented with 100% modulation depth at multikilohertz repetition rate in semiconductor doped glass channel waveguide. An interpretation of the modulation mechanism ...
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A polarisation independent all-optical modulator is presented with 100% modulation depth at multikilohertz repetition rate in semiconductor doped glass channel waveguide. An interpretation of the modulation mechanism is given.
The guiding structures in photonic and integrated optical circuits have complex geometries and refractive-index profiles so that numerical methods must be used to analyze them. When it is necessary to evaluate paramet...
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The guiding structures in photonic and integrated optical circuits have complex geometries and refractive-index profiles so that numerical methods must be used to analyze them. When it is necessary to evaluate parameters such as group delay or dispersion coefficient, which involve first and second derivatives of the numerically calculated propagation constants of the modes, the required accuracy is not easy to obtain. Suitable functions may be used to fit, in a least-squares sense, the numerical solutions and to easily obtain derivatives from a direct analytical calculation. (C) 1994 John Wiley & Sons
Efficient electroabsorption in an InGaAsP/InGaAsP MQW opticalwaveguide modulator structure is reported. A 17 dB extinction ratio is obtained by applying a 3.5 V drive voltage to a 78-mu-m long waveguide operating at ...
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Efficient electroabsorption in an InGaAsP/InGaAsP MQW opticalwaveguide modulator structure is reported. A 17 dB extinction ratio is obtained by applying a 3.5 V drive voltage to a 78-mu-m long waveguide operating at 1.54-mu-m under TE-polarisation mode. The on-state attenuation is only 2 dB.
The analogy between guided modes in planar opticalwaveguides and surface plasmons is worked out. It explains that integrated optical (IO) and surface plasmon (SP) affinity sensors and immunosensors are based on the s...
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The analogy between guided modes in planar opticalwaveguides and surface plasmons is worked out. It explains that integrated optical (IO) and surface plasmon (SP) affinity sensors and immunosensors are based on the same physical effect: changes in the effective refractive index of the guided waves are induced by the interactions of their evanescent field with the analyte molecules binding specifically to reaction partners immobilized on the sensor surface. The sensitivities of IO and SP affinity sensors are derived - as analytical expressions - by perturbation theory;also their sensitivities to refractive index changes, i.e. as differential refractometers. The sensitivities of IO sensors at lambda = 632.8 nm are compared with those of SP sensors with gold films at the same wavelength and silver films at lambda = 632.8 and 780 nm. The highest sensitivities are predicted for IO interferometric sensors.
We present new results in the laser doping of two materials of major interest for applications: LiNbO3 and Si. In both cases a solid dopant source was used. Using a free running ruby laser, we have doped single crysta...
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ISBN:
(纸本)0819418137
We present new results in the laser doping of two materials of major interest for applications: LiNbO3 and Si. In both cases a solid dopant source was used. Using a free running ruby laser, we have doped single crystalline lithium niobate with Ti down to 1.5 micrometers . A step- like Ti profile was determined by Rutherford BAckscattering Spectrometry. Irradiating with a cw CO2 laser Si wafers coated with a P-containing paste, n-p junctions were obtained.
GaAs/AlGaAs multiple quantum well ridge waveguide laser diodes have been fabricated using MOVPE and a dry etch process for the ridge structure. The threshold currents of the lasers are 10-15 mA at 25-degrees-C and the...
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GaAs/AlGaAs multiple quantum well ridge waveguide laser diodes have been fabricated using MOVPE and a dry etch process for the ridge structure. The threshold currents of the lasers are 10-15 mA at 25-degrees-C and the characteristic temperature T(o) exceeds 200 K. Modulation bandwidths of up to 14 GHz and relaxation oscillation frequencies of up to 36 GHz are achieved with these devices. The modulation bandwidth exceeds 10 GHz in a temperature range up to 80-degrees-C.
Thick-film photolithography based on SU-8 has gained great interest in the field of microreplication technologies. For replication applications the SU-8 structures themselves or electroplated copies of the resist stru...
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Thick-film photolithography based on SU-8 has gained great interest in the field of microreplication technologies. For replication applications the SU-8 structures themselves or electroplated copies of the resist structures are used as casting or embossing tools. In this paper, a simple estimation model is proposed to predict the sidewall profiles of SU-8. This model is based oil the effects of Fresnel diffraction and absorption resulting in useful approximations for the pattern profile of SU-8. Its usefulness is successfully verified by experimental results;the estimated and experimental results show similar trends. In addition, by utilizing this model two exposure methods based on reflection and refraction Could be developed which avoid negatively sloped sidewall profiles of SU-8. Using these exposure methods, SU-8 preforms Without undercut for the replication of opticalwaveguides have been achieved.
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