The thesis gives a simulation result of s - shape y - branch structure with numerical computation software and it also meets the demand 本文結(jié)合已有的軟件對(duì)s彎曲結(jié)構(gòu)進(jìn)行了分析模擬,也得到了達(dá)到性能指標(biāo)的分析結(jié)果。
In developing the planar lightwave circuits , the coupling loss between a waveguide with a high refractive index difference and a single mode fiber is considered . a novel spot - size converter based on a y - branch structure is proposed and numerical simulation results indicate that it can reduce the coupling loss effectively with low polarization dependent loss and good fabrication tolerance 在平面波導(dǎo)光器件研制中,提出了高折射率差二氧化硅波導(dǎo)與光纖的新型低損耗連接,與現(xiàn)有波導(dǎo)單側(cè)變窄的結(jié)構(gòu)相比較,有效的降低了連接損耗,同時(shí)具有偏振相關(guān)損耗低,工藝容差性好的優(yōu)點(diǎn)。
Applying an exact modal propagation analysis method and self - imaging theory , i analyzed the principle of mmi coupler . then , the self - imaging effect in graded - index waveguide has been analyzed and simulated using three - dimensional bpm . considering normal technology error , a low loss y - branch structure ( symmetric or asymmetric ) with a multimode waveguide transition section is introduced and designed 在設(shè)計(jì)y分支波導(dǎo)結(jié)構(gòu)時(shí),考慮常規(guī)工藝誤差的影響,引入多模波導(dǎo)作為y分支波導(dǎo)結(jié)構(gòu)的過(guò)渡區(qū),利用參數(shù)空間搜索法來(lái)設(shè)計(jì)結(jié)構(gòu)參數(shù),實(shí)現(xiàn)低損耗的y分支結(jié)構(gòu)。
The numerical and experimental results of this y - branch structure indicate that the proposed y - branch structure , without extra fabrication technologies , has a lower excess loss as compared with the conventional ones . optimal designs of the structural parameters for the multimode interference coupler are carried out . low loss and high uniformity of the multimode interference couplers are achieved when the waveguide is weakly guiding 研究了y分支耦合器中分支頂端間距(為工藝制作方便)帶來(lái)的附加損耗,提出了低損耗新型y分支耦合器結(jié)構(gòu),并給出了相關(guān)結(jié)構(gòu)參數(shù)的優(yōu)化設(shè)計(jì)方法,我們的理論計(jì)算和實(shí)驗(yàn)測(cè)試結(jié)果均表明,該新型結(jié)構(gòu)可以在常規(guī)光波導(dǎo)制作工藝下提高器件的指標(biāo)。