The purpose of this thesis is to design and fabricate vertical mirror reflector. We fabricated semiconductor laser and optical filter by vertical mirror reflector and bended waveguide. By this design, we could bend the incident optical mode and get the power splitter with coupling coefficient is 0, 0.15 and 0.5. In order to make total internal reflection in vertical reflective mirror, we used ICP-RIE dry etching process to fabricate vertical and smooth mirror. By BPM simulation, we showed that the device volume was decreased to 50%. In the semiconductor laser, we fabricated the Fabry-Perot laser by optical waveguide reflector with one input and two inputs. In addition, we also fabricated a reformatory Fabry-Perot laser by the ring resonator with one 3dB coupler, two 90o angle reflectors, and bended waveguide. In the semiconductor optical filter, we design 2¡Ñ2 90o angle reflector whose coupling coefficient is 0.15, and ring resonator with two 2¡Ñ2 90o reflector and bended waveguide. In fabrication process, first, we defined the device pattern by using photo-lithography technique. Second, we etched ridge waveguide by using dry etching and wet etching method. In order to decrease the scattering loss, we deep etched bended waveguide and the reflector. Then, we etched the reflector mirror by ICP-RIE dry etching process. Finally, we used polyimide to flatten the sides of the ridge waveguide and evaporated metal electrode. In the device characteristic, we obtained a power splitter with 65 percent and 35 percent output. It demonstrates that the light was reflected from reflective mirror to output port.

In this thesis, S-bend waveguides and ring resonant filters with multimode interference (MMI) couplers have been designed and fabricated. The single-ring filters are designed to have free spectral ranges ( FSR's) of 33.3GHz, 40GHz and 50GHz. The FSR's of double-ring filters are 100GHz and 200GHz. The splitting ratios of the 9-

The purpose of this thesis is to develop ring resonators with simple processes and integration. We used loop mirror as a reflector in the semiconductor lasers. In the material, a 1.55£gm symmetric quantum well InGaAsP epi-layer is used to fabricate the lasers. In device design, we designed four kinds of semiconductor lasers by using loop mirror and cleaved facet. The curvature radiuses are 160 and 260£gm that are presented to investigate bending loss and material loss. In the input/output we had an inclined 7 degree to avoid interference. We also designed another two semiconductor lasers by using ring resonator and cleaved facet. Applying the resonance characteristic of ring resonator can achieve wavelength selection and filtering. In fabrication process, we developed new etching technique. The ICP-RIE dry etching and wet etching method were used in the process. Fist we etched half of the total depth by ICP-RIE dry etching. And then the multi-step technique was used to approach the expecting depth. Beside, we had extra deep wet etching process in MMI. Finally, we used the etching solution HBr:HCl:H2O2:H2O =5:4:1:70 to smooth the sidewall and reduce the scattering loss. In device characteristic, we obtained differential quantum efficiency of 20£gW/mA for the 1000£gm straight waveguide laser. We can not observe laser characteristics for the loop mirror laser, partly because of the high loss in bending section.

The purpose of this research is to present design and fabrication of resonant loop-mirror Fabry-Perot lasers. Single filter has simple fabrication processes and good potential for intergration. A 1.55-£gm symmetric quantum well InGaAlAs epi-layer wafer is used to fabricate the laser. In device design, we apply loop mirror to obtain reflection instead of cleaved facet and take 1x2, 2x2 Multi-Mode Interference (MMI) with different splitting ratio (50%:50%¡F15%:85%) as a coupler. Then we combine MMI couplers with ring cavities to reflect specific wavelength at particular position. Therefore we can obtain semiconductor laser with property of wavelength-selection filter. In this design of the mask, we add a mask of deep-etch around MMI in order to decrease the loss of higher mode inside MMI. In the part of devices design, we apply multi-step technology for wet etch to obtain necessary depth. Finally, we use the etch solution (HBr¡GHCl¡GH2O2¡GH2O¡×5¡G4¡G1¡G70) to smooth the sidewall of the waveguide, and to reduce scattering loss of the device. In the part of planarization, we can adhere dummy wafers to surround the main sample and extend the total area. If we can fill the gap flat, the problem of high edge by spinning will be solved. However, we were not able to fill the gap.

This study uses vertical mirror optical waveguide reflector and bending waveguide to fabricate semiconductor ring resonators. By using multimode interference couplers with specific width and length that generate distinctive energy distribution to achieve the power splitting of 85:15. We integrate vertically deep etching turning mirror to reflect optical mode, and reduce the component size to 37.6%. In fabrication process, this study applies multiple wet etching technique to form the waveguide structure. First, we use wet etching technique to etch ridge waveguide and turning mirror, and then perform deep etching in the periphery of bending and turning region to reduce the bending loss. Finally, the etching mask is lifted off, and the wafer is polished and sliced for measurement. After measuring the signal, we can compute waveguide loss by Fabry-perot resonant situation. The waveguide loss is 59.6dB/cm. Power splitting of 90:10 is achieved. The free spectral range (FSR) is 72GHz for the ring resonators.

Dielectric permittivity measurements provide important input to engineering and scientific disciplines due to the effects of permittivity on the interactions between electromagnetic energy and materials. A novel ring resonator design is presented for the measurement of permittivity of low dielectric constant foams. A review of dielectric material properties and currently available measurement methods is included. Measurements of expanded polystyrene are reported and compared with results from the literature; good agreement between measurements and published results is shown.

SOI-based micro-ring resonators can be ultra-compact and highly sensitive for sensing applications. In order to obtain deeper notches and enlarge the detection area, the concentric double-ring resonators have been proposed. To further increase the sensing area and promote the sensing sensitivity, we add one more inner ring into the double-ring structure to form the triple-ring resonator. In this thesis, we have derived the transfer functions of the multi-ring structures and calculated the resonance properties of the triple-ring resonators by using the 3-D FDTD method. We have investigated the effects of the ring radius on the transmission spectra and discussed the variations of spectral response between the double-ring and triple-ring resonators. We also demonstrate the applications of the triple-ring resonator as the refractive index sensors. The triple-ring resonator can obtain deeper dips and higher detection sensitivity of 12.85 nm/RIU. Enlarging the gap can increase the sensing area and is shown to be able to promote the sensing sensitivity. Besides, the influences of the light polarization and the optical absorption on the spectral responses have been discussed as well.

A procedure is introduced for increasing the sensitivity of measurements in integrated ring resonators beyond what has been previously accomplished. This is demonstrated by a high-frequency, phase sensitive lock to the ring resonators. A prototyped fiber Fabry-Perot cavity is used for comparison of the method to a similar cavity. The Pound-Drever-Hall (PDH) method is used as a proven, ultra-sensitive method with the exploration of a much higher frequency modulation than has been previously discussed to overcome comparatively low finesse of the ring resonator cavities. The high frequency facilitates the use of the same modulation signal to separately probe the phase information of different integrated ring resonators with quality factors of 8.2 x10^5 and 2.4 x10^5. The large free spectral range of small cavities and low finesse provides a challenge to sensing and locking the long-term stability of diode lasers due to small dynamic range and signal-to-noise ratios. These can be accommodated for by a calculated increase in modulation frequency using the PDH approach. Further, cavity design parameters will be shown to have a significant affect on the resolution of the phase-sensing approach. A distributed feedback laser is locked to a ring resonator to demonstrate the present sensitivity which can then be discussed in comparison to other fiber and integrated sensors. The relationship of the signal-to-noise ratio (S/N) and frequency range to the cavity error signal will be explored with an algorithm to optimize this relationship. The free spectral range and the cavity transfer function coefficients provide input parameters to this relationship to determine the optimum S/N and frequency range of the respective cavities used for locking and sensing. The purpose is to show how future contributions to the measurements and experiments of micro-cavities, specifically ring resonators, is well-served by the PDH method with high-frequency modulation.

A procedure is introduced for increasing the sensitivity of measurements in integrated ring resonators beyond what has been previously accomplished. This is demonstrated by a high-frequency, phase sensitive lock to the ring resonators. A prototyped fiber Fabry-Perot cavity is used for comparison of the method to a similar cavity. The Pound-Drever-Hall (PDH) method is used as a proven, ultra-sensitive method with the exploration of a much higher frequency modulation than has been previously discussed to overcome comparatively low finesse of the ring resonator cavities. The high frequency facilitates the use of the same modulation signal to separately probe the phase information of different integrated ring resonators with quality factors of 8.2 x10^5 and 2.4 x10^5. The large free spectral range of small cavities and low finesse provides a challenge to sensing and locking the long-term stability of diode lasers due to small dynamic range and signal-to-noise ratios. These can be accommodated for by a calculated increase in modulation frequency using the PDH approach. Further, cavity design parameters will be shown to have a significant affect on the resolution of the phase-sensing approach. A distributed feedback laser is locked to a ring resonator to demonstrate the present sensitivity which can then be discussed in comparison to other fiber and integrated sensors. The relationship of the signal-to-noise ratio (S/N) and frequency range to the cavity error signal will be explored with an algorithm to optimize this relationship. The free spectral range and the cavity transfer function coefficients provide input parameters to this relationship to determine the optimum S/N and frequency range of the respective cavities used for locking and sensing. The purpose is to show how future contributions to the measurements and experiments of micro-cavities, specifically ring resonators, is well-served by the PDH method with high-frequency modulation.

Scientists and engineers measure dielectric constant because it gives them better understanding of materials and helps them to know how to integrate these materials into their design processes;it also helps them to shorten design life cycle,and aside these two functions,it has numerous uses all of which cannot be enumerated in this section.Owing to its usefulness,various measurement methods of dielectric constant of materials have been developed over the years.Each method has its limitations which affect the accuracy of the measurement;these limitations range from frequency,temperature,and  mearsurement environment to material under test.   In this thesis,four most common methods of measuring dielectric constant were discussed and the most accurate one,the resonant method,was chosen and worked on .The project was executed by making a mathematical analysis of the ring resonator which was later simulated in HFSS to get results which would be comparable to ones obtained in  laboratory measurements.   The ring was fabricated and taken to the laboratory for measurement.Two monopole antennas were connected to the two ports of a VNA with one antenna serving as the transmitter and the other serving as the receiver.   The resonant frequencies obtained were combined with the geometric parameters of the ring resonator and that of the MUT in equations written into MATLAB scripts;this equations were used to extract the dielectric constant of the MUT.