Abubuwan da ba su da amfani na Silicon Photonics

Silicon photonicsabubuwan da ba su da amfani

Akwai muhimman abubuwa da dama a cikin silicon photonics. Ɗaya daga cikinsu shine mahaɗin grating mai fitar da saman, kamar yadda aka nuna a Hoto na 1A. Ya ƙunshi wani ƙarfi grating a cikin jagorar waveguide wanda lokacinsa yayi daidai da tsawon raƙuman haske a cikin jagorar waveguide. Wannan yana ba da damar fitar da hasken ko karɓarsa a tsaye zuwa saman, wanda hakan ya sa ya dace da ma'aunin matakin wafer da/ko haɗawa da zare. Maɗaurin grating sun bambanta da silicon photonics saboda suna buƙatar babban bambanci a tsaye. Misali, idan kuna ƙoƙarin yin mahaɗin grating a cikin jagorar waveguide na gargajiya na InP, hasken yana zube kai tsaye cikin substrate maimakon a fitar da shi a tsaye saboda jagorar waveguide yana da matsakaicin matsakaicin refractive index fiye da substrate. Don sa ya yi aiki a cikin InP, dole ne a haƙa kayan a ƙarƙashin grating don dakatar da shi, kamar yadda aka nuna a Hoto na 1B.

Hoto na 1: mahaɗan grating masu fitowa a saman silikon (A) da InP (B). A cikin (A), launin toka da shuɗi mai haske suna wakiltar silikon da silikon, bi da bi. A cikin (B), ja da lemu suna wakiltar InGaAsP da InP, bi da bi. Hotuna (C) da (D) suna duba hotunan na'urar hangen nesa ta lantarki (SEM) na mahaɗan grating na InP da aka dakatar.

Wani muhimmin sashi shine mai canza girman tabo (SSC) tsakaninjagorar raƙuman ganida kuma zare, wanda ke canza yanayin kusan 0.5 × 1 μm2 a cikin jagorar wave silicon zuwa yanayin kusan 10 × 10 μm2 a cikin zaren. Hanya ta yau da kullun ita ce amfani da tsari da ake kira taper mai juyawa, wanda jagorar wave ke raguwa a hankali zuwa ƙaramin tip, wanda ke haifar da faɗaɗa mai yawa nana ganifacin yanayin. Ana iya kama wannan yanayin ta hanyar jagorar gilashin da aka dakatar, kamar yadda aka nuna a Hoto na 2. Tare da irin wannan SSC, asarar haɗin gwiwa na ƙasa da 1.5dB ana iya cimma ta cikin sauƙi.

Hoto na 2: Mai canza girman tsari don jagororin igiyar silicon. Kayan silicon yana samar da tsarin mazugi mai juyi a cikin jagorar igiyar gilashin da aka dakatar. An cire murfin silicon a ƙarƙashin jagorar igiyar gilashin da aka dakatar.

Babban ɓangaren da ba ya aiki shi ne mai raba hasken polarization. An nuna wasu misalan masu raba hasken polarization a Hoto na 3. Na farko shine ma'aunin Mach-Zender interferometer (MZI), inda kowane hannu yana da birefringence daban-daban. Na biyu shine mai haɗa hanya mai sauƙi. Siffar birefringence na jagorar igiyar silicon ta yau da kullun tana da girma sosai, don haka ana iya haɗa hasken polarized mai ratsa jiki (TM) gaba ɗaya, yayin da hasken polarized mai ratsa jiki (TE) kusan ba za a iya haɗa shi ba. Na uku shine ma'aunin grating, inda aka sanya zare a kusurwa don a haɗa hasken polarized TE a gefe ɗaya kuma a haɗa hasken polarized TM a ɗayan. Na huɗu shine ma'aunin grating mai girma biyu. Yanayin fiber waɗanda filayen lantarki suke daidai da alkiblar yaɗuwar jagorar waveguide an haɗa su da jagorar waveguide mai dacewa. Ana iya karkatar da zare ɗin kuma a haɗa shi da jagororin waveguide guda biyu, ko kuma a daidaita shi da saman sannan a haɗa shi da jagororin waveguide guda huɗu. Wani ƙarin fa'ida na mahaɗan grating masu girma biyu shine cewa suna aiki azaman masu juyawa na polarization, ma'ana cewa duk hasken da ke kan guntu yana da polarization iri ɗaya, amma ana amfani da polarizations guda biyu na orthogonal a cikin zare.

Hoto na 3: Masu raba polarization da yawa.