In recent years, the silica-on-silicon based multimode interference （MMI） optical waveguide is an interesting research topic. It is being advanced various researches on the silica based MMI coupler. This paper repre...In recent years, the silica-on-silicon based multimode interference （MMI） optical waveguide is an interesting research topic. It is being advanced various researches on the silica based MMI coupler. This paper represents the considerations of the optimal design of the silica-on-silicon based MMI optical coupler for better performance. For that, we have illustrated the simulation results on a particular case of the 4x4 silica-on-silicon based MMI coupler. From the simulation results, it is seen that the performance of the MMI coupler depends on multiple width and length combinations of the MMI waveguide. The results also show that the width of the multimode waveguide could not be too small or too large for optimal performance, and at the widths, 100~tm, 120~tm and 130~tm, the performance could be optimized and be almost 0.62 - 0.64 in a given length range. Finally, the results have been compared with the optical coupler presently available in the market and show that the silica-on-silicon based MMI coupler is much more efficient in terms of losses and the performance associated with it and the size of the coupler.展开更多
Optical waveguides in silica-on-silicon are one of the key elements in optical communications.The processes of deep etching silica waveguides using resist and metal masks in RIE plasma are investigated.The etching res...Optical waveguides in silica-on-silicon are one of the key elements in optical communications.The processes of deep etching silica waveguides using resist and metal masks in RIE plasma are investigated.The etching responses,including etching rate and selectivity as functions of variation of parameters,are modeled with a 3D neural network.A novel resist/metal combined mask that can overcome the single-layer masks’ limitations is developed for enhancing the waveguides deep etching and low-loss optical waveguides are fabricated at last.展开更多
An experimental study of the dependence of SiO2 waveguide side wall roughness on the etch condi- tions and etch masks in CHF3/O2 based reactive ion etching plasma was reported. When working under standard low-pressure...An experimental study of the dependence of SiO2 waveguide side wall roughness on the etch condi- tions and etch masks in CHF3/O2 based reactive ion etching plasma was reported. When working under standard low-pressure （20mtorr） etching conditions, a novel etch roughening phenomenon has been observed in the plasma, that is, the roughness of the etched front surface increases with the amount of material etched, independent of etch rate, RF power, and gas composition. Besides, the etched underlying side wall will be tapered as the upper SU-8 resist pattern degradation transfers downward. A process using double-layered mask, consisting of SU-8 resist and thin Chromium film, was developed for improving the side wall smoothness. Based on the studies, SiO2/Si channel waveguides with the propagation loss less than 0. 07dB/cm were fabricated at last.展开更多
文摘In recent years, the silica-on-silicon based multimode interference （MMI） optical waveguide is an interesting research topic. It is being advanced various researches on the silica based MMI coupler. This paper represents the considerations of the optimal design of the silica-on-silicon based MMI optical coupler for better performance. For that, we have illustrated the simulation results on a particular case of the 4x4 silica-on-silicon based MMI coupler. From the simulation results, it is seen that the performance of the MMI coupler depends on multiple width and length combinations of the MMI waveguide. The results also show that the width of the multimode waveguide could not be too small or too large for optimal performance, and at the widths, 100~tm, 120~tm and 130~tm, the performance could be optimized and be almost 0.62 - 0.64 in a given length range. Finally, the results have been compared with the optical coupler presently available in the market and show that the silica-on-silicon based MMI coupler is much more efficient in terms of losses and the performance associated with it and the size of the coupler.
文摘Optical waveguides in silica-on-silicon are one of the key elements in optical communications.The processes of deep etching silica waveguides using resist and metal masks in RIE plasma are investigated.The etching responses,including etching rate and selectivity as functions of variation of parameters,are modeled with a 3D neural network.A novel resist/metal combined mask that can overcome the single-layer masks’ limitations is developed for enhancing the waveguides deep etching and low-loss optical waveguides are fabricated at last.
文摘An experimental study of the dependence of SiO2 waveguide side wall roughness on the etch condi- tions and etch masks in CHF3/O2 based reactive ion etching plasma was reported. When working under standard low-pressure （20mtorr） etching conditions, a novel etch roughening phenomenon has been observed in the plasma, that is, the roughness of the etched front surface increases with the amount of material etched, independent of etch rate, RF power, and gas composition. Besides, the etched underlying side wall will be tapered as the upper SU-8 resist pattern degradation transfers downward. A process using double-layered mask, consisting of SU-8 resist and thin Chromium film, was developed for improving the side wall smoothness. Based on the studies, SiO2/Si channel waveguides with the propagation loss less than 0. 07dB/cm were fabricated at last.
