平顶和陡峭带边响应的窄带热光调谐Fabry-Perot滤波器

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Fabry-Perot microcavity modes observed in the micro-photoluminescence spectra of the single nanowire with InGaAs/GaAs heterostructure

We report on the fabrication of the nanowires with InGaAs/GaAs heterostructures on the GaAs(111) B substrate using selective-area metal organic vapor phase epitaxy. Fabry-Perot microcavity modes were observed in the nanowires with perfect end facets dispersed onto the silicon substrate and not observed in the free-standing nanowires. We find that the calculated group refractive indices only considering the material dispersion do not agree with the experimentally determined values although this method was used by some researchers. The calculated group refractive indices considering both the material dispersion and the waveguide dispersion agree with the experimentally determined values well. We also find that Fabry-Perot microcavity modes are not observable in the nanowires with the width less than about 180 nm, which is mainly caused by their poor reflectivity at the end facets due to their weak confinement to the optical field. (C) 2009 Optical Society of America

Fourier series expansion method for gain measurement from amplified spontaneous emission spectra of Fabry-Perot semiconductor lasers

A gain measurement technique, based on Fourier series expansion of periodically extended single fringe of the amplified spontaneous emission spectrum, is proposed for Fabry-Perot semiconductor lasers. The underestimation of gain due to the limited resolution of the measurement system is corrected by a factor related to the system response function. The standard deviations of the gain-reflectivity product under low noise conditions are analyzed for the Fourier series expansion method and compared with those of the Hakki-Paoli method and Cassidy's method. The results show that the Fourier series expansion method is the least sensitive to noise among the three methods. The experiment results obtained by the three methods are also presented and compared.

A Si-based tunable narrow-band flat-top filter with multiple-step-type Fabry-Perot cavity structure

In the optical network, the quick and accurate alignment with wavelength is an important issue during the channel detection. At this point, a filter having flat-top response characteristic is an effective solution. Based on multiple-step-type Fabry-Perot cavity structure, a novel all-Si-based thermooptical tunable flat-top filter with narrow-band has been fabricated, using our patent silicon-on-reflector bonding technology. The device demonstrated a 1-dB flat-top width of 1 nm, 3-dB band of 3 nm, free spectra range of 8 nm, and the tuning range of 4.6 nm was obtained under the applied voltage of 4 V.

A new method of restraining the Fabry-Perot resonance

In the paper, we present a new method of restraining the Fabry-Perot resonance. The method is to combine dip angle with taper angle in the structure of the device and avoids the process of antireflection coatings. The experimental results show that restraining effect is apparent. A high threshold current has been obtained for the sample with both dip angle and taper angle structure. It provides a new method to make traveling-wave optical amplifiers.

The effect of Fabry-Perot interference on the packaging of SOI-based optoelectronic devices

During the packaging of optoelectrome device, a problem always met is the instability of output power. The main effect causing this problem, Fabry-Perot interference, is discussed in this paper. Both theoretical analysis and experimental test are carried out and in good agreement. As an example of avoiding the disadvantage of Fabry-Perot interference, the packaging process of Silicon-on-Insulator (SOI) based Variable Optical Attenuator(VOA) is shown at last.

The mode control of asymmetric Fabry-Perot optical modulators with multiple quantum wells

The asymmetric Fabry-Perot (ASFP) mode position with the thickness of different index coating layer is calculated. The reason for the blue shift of the ASFP mode with the increasing thickness of low index coating layer is analyzed and this phenomenon is observed in experiments. With the wet-etching method, the ASFP mode can be tuned to the desired wavelength and thus the deviation of growth can be compensated. This method is used to improve the contrast ratio of modulators. With the ASFP mode located at different positions relative to the unbiased e-hh peak, different modulation characteristics are demonstrated.

平顶响应的热光可调谐Fabry-Perot滤波器

制作了一种平顶响应的热光可调谐滤波器,通过用湿法腐蚀方法将半波长的共振腔分成具有不同光学厚度的两部分,并且使入射光照射到两部分的面积基本上相等,实现平顶响应特性.对该滤波器的输出响应进行检测,实验结果与理论模拟符合,相对透射率的极大值与极小值间的起伏度小于0.01.与实现平顶响应的其他方法相比,本滤波器器件的制作工艺简单,平顶性能优越,容易与其他有源和无源光子器件集成.还给出了制作几十μm量级的共振腔实现平顶窄带响应的热光可调谐滤波器的机理,其输出响应的起伏度小于0.02,3 dB带宽小于1 nm.

1.55μm Fabry-Perot Thermo-Optical Tunable Filter with amorphous-Si as Cavity

A 1.55μm Fabry-Perot (F-P) thermo-optical tunable filter is fabricated. The cavity is made of amorphous silicon (a-Si) layer grown by electron-beam evaporation technique. Due to the excellent thermo-optical property of a-Si, the refractive index of the F-P cavity will be changed by heating; the transmittance resonant peak will therefore shift substantially. The measured tuning range is 12nm, FWHM (full-width-at-half-maximum) of the transmission peak is 9nm, and heating efficiency is 0.1K/mW. The large FWHM is mainly due to the non-ideal coating deposition and mirror undulation. Possible improvements to increase the efficiency of heating are suggested.

Tunability of resonant wavelength by Fabry-Perot microcavity in organic light-emitting diodes

Distributed Bragg reflectors (DBR) with different reflection wavelengths were designed, and were used to fabricate microcavity organic light-emitting diodes (OLEDs) based on tris(8-hydroxyquinoline)-aluminum (Alq(3)) as the emitter and N, N'-di(naphthalene-1-yl)-N, N'-diphenyl-benzidine (NPB) as the hole-transporting layer. The microcavity was composed of DBR dielectric mirror and metal electrode aluminum (Al) mirror. Some effects of vertical optical Fabry-Perot microcavity on spontaneous emission in OLEDs were investigated. Spectral narrowing, enhancement of emitting intensity and anglular dependence of emission were observed due to the microcavity effect. It was found experimentally that the utilization of DBR is a better method to adjust the emissive mode in the resonant cavity in OLEDs well. Thus the realization of different color light emission becomes possible by the combination of carefully designed microcavity and electroluminescent organic semiconductors in a single LED.

A Fabry-Perot Refractometer for Chemical Vapor Sensing by Solid-Phase Microextraction

The contour lithography method [1] is used to improve the fabrication yield of previously demonstrated [2] microfluidic Fabry-Perot (FP) refractive index (RI) sensors. The sensors are then coated with polydimethylsiloxane (PDMS) based polymers to detect vapor analytes by solid-phase microextraction (SPME). Preliminary characterization of devices coated with two different polymers and exposed to xylenes vapors yields a maximum sensitivity of 0.015 nm/ppm and a detection limit below 120 ppm.

Design Method for Circularly Polarized Fabry-Perot Cavity Antennas

A new class of circularly polarized (CP) Fabry-Perot cavity antennas is introduced that maintain the simplicity of a linearly polarized primary feed and a single cavity structure. The proposed antennas employ a double-sided partially reflective surface (PRS), which allows independent control of the magnitude and phase responses for the reflection and transmission coefficients. In conjunction with an anisotropic high-impedance surface (HIS) ground plane, this arrangement allows for the first time a single cavity antenna to produce a specified gain in CP from a linearly polarized primary source. A design procedure for this class of antennas is introduced. The method exploits a simple ray optics model to calculate the magnitude and phase of the electric field in the cavity upon plane wave excitation. Based on this model, analytical expressions are derived, which enforce the resonance condition for both polarizations at a predetermined PRS reflectivity (and hence predetermined antenna gain) together with a 90 degrees differential phase between them. The validity of the concept is confirmed by means of an example entailing an antenna with gain of approximately 21 dB at 15 GHz. Full-wave simulation results and experimental testing on a fabricated prototype are presented and agree well with the theoretical predictions.