ﺟﺬب ﮐﻨﻨﺪه ﭘﻼﺳﻤﻮﻧﯽ دو ﺑﺎﻧﺪي ﻣﺒﺘﻨﯽ ﺑﺮ ﮔﺮاﻓﻦ ﺑﺮاي ﮐﺎرﺑﺮد در ادوات ﻣﺨﺎﺑﺮات ﻧﻮري

Design of a Dual Band Graphene-Plasmonic Absorber for Optical Communication Devices

ﭼﮑﯿﺪه: ﺿﺮﯾﺐ ﺟﺬب ﻧﻮري ﯾﮏ ﭘﺎراﻣﺘﺮ ﮐﻠﯿﺪي در ﻋﻤﻠﮑﺮد ﻣﻮﻓﻘﯿﺖ آﻣﯿﺰ ادوات اﻟﮑﺘﺮوﻧﯿﮏ ﻧﻮري ﻧﻈﯿﺮ آﺷﮑﺎرﺳﺎزﻫﺎ، ﺳﻠﻮ ل ﻫﺎي ﺧﻮرﺷﯿﺪي، ﻣﺪوﻻﺗﻮرﻫﺎ، ﻓﯿﻠﺘﺮﻫﺎ اﺳﺖ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر در اﯾﻦ ﻣﻘﺎﻟﻪ، ﯾﮏ ﺟﺬب ﮐﻨﻨﺪه دو ﺑﺎﻧﺪي ﻣﺘﺸﮑﻞ از ﯾﮏ ﺳﺎﺧﺘﺎر ﻓﻠﺰ- ﮔﺮاﻓﻦ- دي اﻟﮑﺘﺮﯾﮏ- ﻓﻠﺰ ﮐﻪ در ﻃﻮل ﻣﻮج ﻫﺎي ﻣﺨﺎﺑﺮات ﻧﻮري ﮐﺎر ﻣﯽ ﮐﻨﺪ، اراﺋﻪ ﺷﺪه اﺳﺖ. ﺟﻬﺖ ﺑﻪ دﺳﺖ آوردن ﻣﺸﺨﺼﻪ ﺟﺬب ﺳﺎﺧﺘﺎر ﭘﯿﺸﻨﻬﺎدي از روش ﺗﻔﺎﺿﻞ ﻣﺤﺪود در ﺣﻮزه زﻣﺎن اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ، ﺗﺄﺛﯿﺮ ﺿﺨﺎﻣﺖ ﻧﺎﻧﻮﺳﺎﺧﺘﺎر ﻓﻠﺰي روﯾﯽ، ﻻﯾﻪ ﻫﺎي دي اﻟﮑﺘﺮﯾﮏ و زﯾﺮﻻﯾﻪ ﻓﻠﺰي ﺑﺮ ﻣﺸﺨﺼﻪ ﺟﺬب ﻧﻮر در ﺳﺎﺧﺘﺎر ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. اﺳﺘﻔﺎده از ﮔﺮاﻓﻦ ﺗﮏ ﻻﯾﻪ ﻫﻤﺮاه ﺑﺎ ﺳﺎﺧﺘﺎر ﭘﻼﺳﻤﻮﻧﯽ ﺳﺒﺐ ﺑﻬﺒﻮد ﺑﺮﻫﻢ ﮐﻨﺶ ﻧﻮر و ﮔﺮاﻓﻦ ﺷﺪه و در ﻧﺘﯿﺠﻪ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺟﺬب ﻧﻮر در ﺳﺎﺧﺘﺎر ﺷﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺑﺮاي اﯾﻦ ﺳﺎﺧﺘﺎر، ﺟﺬب ﻧﻮر 95% در ﻃﻮل ﻣﻮج 1310nm و ﺟﺬب ﻧﻮر 97% در ﻃﻮل ﻣﻮج 1675nm ﺑﻪ دﺳﺖ ﻣﯽ آﯾﺪ. ﺑﻨﺎﺑﺮاﯾﻦ، اﯾﻦ ﺟﺬب ﮐﻨﻨﺪه ﻗﺎﺑﻠﯿﺖ ﮐﺎر در دو ﺑﺎﻧﺪ ﻣﺨﺎﺑﺮات ﻧﻮري )ﺑﺎﻧﺪ O و ﺑﺎﻧﺪ U( ﺑﻪ ﻃﻮر ﻫﻤﺰﻣﺎن را دارا اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﻣﺪار ﻣﻌﺎدل ﻓﺮﮐﺎﻧﺴﯽ ﺟﺬب ﮐﻨﻨﺪه ﭘﯿﺸﻨﻬﺎدي ﻧﯿﺰ اراﺋﻪ ﺷﺪه اﺳﺖ ﮐﻪ ﻧﺘﺎﯾﺞ ﺧﺮوﺟﯽ آن ﺗﻄﺎﺑﻖ ﺑﺴﯿﺎر ﺧﻮﺑﯽ ﺑﺎ ﻧﺘﺎﯾﺞ ﺷﺒﯿﻪ ﺳﺎزي دارد.

In optoelectronic devices such as photodetectors, solar cells, modulators, filters, etc., the optical absorption coefficient is a key parameter in successful device operation. To this end, in this paper, a dual band absorber, consisting of a metal-graphene-dielectric-metal structure which can operate at communication bands is presented. First of all, the light absorption characteristic has been achieved by finite difference time domain method and then the influences of the thicknesses of top metallic structure, dielectric and substrate layers on the light absorption of the structure have been analyzed. The results revealed that utilizing the graphene monolayer and the plasmonic structure improves the light-graphene interaction and in result, the graphene layer absorption. It is shown that the proposed structure has the light absorption of 95% at the wavelength of 1310nm and the light absorption of 96% at the wavelength of 1675nm. Therefore, this absorber has the ability of operating at two optical communication bands (O-band and U-band) simultaneously.