ʻenehana kumu laser no ka ʻike ʻana i ka fiber optical Mahele ʻEkahi

ʻenehana kumu laser nopuluniu makaike ana i ka Mahele Ekahi

ʻO ka ʻenehana hoʻomaʻamaʻa ʻana i ka fiber optical kahi ʻano o ka ʻenehana ʻike i hoʻomohala ʻia me ka ʻenehana fiber optical a me ka ʻenehana kamaʻilio fiber optical, a ua lilo ia i hoʻokahi o nā lālā ikaika loa o ka ʻenehana photoelectric. ʻO ka ʻōnaehana ʻike fiber Optical ka nui o ka laser, ka fiber transmission, sensing element a i ʻole modulation area, ʻike kukui a me nā ʻāpana ʻē aʻe. ʻO nā palena e wehewehe ana i nā hiʻohiʻona o ka nalu māmā e pili ana i ka ikaika, ka lōʻihi o ka nalu, ka pae, ke kūlana polarization, a me nā mea ʻē aʻe. No ka laʻana, i ka wā e hoʻopili ai ka wela, ka ʻāʻī, ke kaomi, ka manawa, ka neʻe ʻana, ka haʻalulu, ka hoʻololi ʻana, ka piko a me ka nui kemika i ke ala opua, e loli like kēia mau ʻāpana. Hoʻokumu ʻia ka ʻike fiber Optical ma ka pilina ma waena o kēia mau ʻāpana a me nā mea o waho e ʻike ai i nā nui kino kūpono.

Nui nā ʻano opuna laserhoʻohana ʻia i nā ʻōnaehana ʻike fiber optical, hiki ke hoʻokaʻawale ʻia i ʻelua mau ʻāpana: coherentpuna lasera me na kumu malamalama incoherent, incoherentnā kumu māmāʻO ka nui o nā kukui incandescent a me nā kukui-emitting diodes, a me nā kumu kukui coherent me nā laser paʻa, nā lasers wai, nā lasers gas,laser semiconductorafiber laser. ʻO kēia ka mea nui no kapuna kukui laserhoʻohana nui ʻia i ke kahua o ka fiber sensing i nā makahiki i hala iho nei: ka laulā laina haiki i hoʻokahi-frequency laser, hoʻokahi-lōʻihi sweep frequency laser a me ka laser keʻokeʻo.

1.1 Koi no ka laina laina haikinā kumu kukui laser

ʻAʻole hiki ke hoʻokaʻawale ʻia ʻo Optical fiber sensing system mai ke kumu laser, e like me ke ana ʻana i ka hawewe kukui uila, ke kumu kukui laser ponoʻī i ka hana, e like me ka paʻa o ka mana, ka laina laina laser, ka walaʻau ʻana a me nā ʻāpana ʻē aʻe ma ka mamao o ka ʻōnaehana optical fiber sensing, ʻike. ʻO ka pololei, ka naʻau a me nā hiʻohiʻona walaʻau he mea koʻikoʻi. I nā makahiki i hala iho nei, me ka hoʻomohala ʻana i nā ʻōnaehana ʻike fiber optical fiber lōʻihi lōʻihi, ua kau ka ʻoihana a me ka ʻoihana i nā koi koʻikoʻi no ka hana linewidth o ka miniaturization laser, ka mea nui ma: optical frequency domain reflection (OFDR) hoʻohana i ka ʻenehana. ʻenehana ʻike maka e kālailai i nā hōʻailona hoʻopuehu backrayleigh o nā fiber optical i loko o ke kikowaena alapine, me ka uhi ākea (mau tausani mika). ʻO nā mea maikaʻi o ka hoʻonā kiʻekiʻe (milimeter-level resolution) a me ka naʻau kiʻekiʻe (a hiki i -100 dBm) ua lilo i hoʻokahi o nā ʻenehana me nā manaʻo noi ākea i ke ana ʻana o ka fiber optical a me ka ʻenehana ʻike. ʻO ke kumu o ka ʻenehana OFDR ʻo ia ka hoʻohana ʻana i ke kumu kukui tunable e hoʻokō i ke kani ʻana o ka optical frequency, no laila ke hoʻoholo nei ka hana o ke kumu laser i nā kumu nui e like me ka pae ʻike OFDR, ʻike a me ka hoʻonā. Ke kokoke ka mamao o ke kiko noʻonoʻo i ka lōʻihi pili, e hoʻemi nui ʻia ka ikaika o ka hōʻailona beat e ka coefficient τ/τc. No kahi kumu kukui Gaussian me ke ʻano spectral, i mea e hōʻoia ai i ka ʻike ʻana o ke alapine beat ma mua o 90% ʻike, ʻo ka pilina ma waena o ka laulā laina o ke kumu kukui a me ka lōʻihi o ka ʻike e hiki ai i ka ʻōnaehana ke hoʻokō ʻo Lmax~0.04vg. /f, ʻo ia hoʻi, no ka fiber me ka lōʻihi o 80 km, ʻo ka laulā laina o ke kumu kukui ma lalo o 100 Hz. Eia kekahi, ʻo ka hoʻomohala ʻana i nā noi ʻē aʻe e kau i mua i nā koi kiʻekiʻe no ka laina laina o ke kumu kukui. No ka laʻana, ma ka ʻōnaehana hydrophone fiber optical, ʻo ka laina laina o ke kumu kukui e hoʻoholo i ka walaʻau ʻōnaehana a hoʻoholo pū i ka hōʻailona hiki ke ana ʻia o ka ʻōnaehana. Ma Brillouin optical time domain reflector (BOTDR), ʻo ka hoʻonā ana o ka mahana a me ke koʻikoʻi e hoʻoholo nui ʻia e ka laina laina o ke kumu kukui. I loko o ka resonator fiber optic gyro, hiki ke hoʻonui ʻia ka lōʻihi coherence o ka nalu māmā ma ka hōʻemi ʻana i ka laulā laina o ke kumu kukui, ma laila e hoʻomaikaʻi ai i ka fineness a me ka hohonu resonance o ka resonator, e hōʻemi ana i ka laulā laina o ka resonator, a me ka hōʻoia ʻana i ke ana. pololei o ka fiber optic gyro.

1.2 Nā koi no nā kumu laser kahili

ʻO ka laser sweep hoʻokahi i hiki ke hoʻololi i ka nui o ka hawewe nalu lōʻihi, hoʻemi i ke kumukūʻai o ke kūkulu ʻana i ka ʻōnaehana, he ʻāpana koʻikoʻi o ka ʻōnaehana ʻike fiber optical. No ka laʻana, i ka trace gas fiber sensing, ʻokoʻa nā ʻano kinoea like ʻole i nā kiʻekiʻe absorption kinoea. I mea e hōʻoiaʻiʻo ai i ka maikaʻi o ka absorption māmā i ka wā e lawa ai ke ana kinoea a loaʻa ka ʻike kiʻekiʻe o ke ana ʻana, pono ia e hoʻohālikelike i ka lōʻihi o ka nalu o ke kumu kukui hoʻouna me ke kiʻekiʻe absorption o ka mole kinoea. ʻO ke ʻano o ke kinoea hiki ke ʻike ʻia e hoʻoholo pono ʻia e ka lōʻihi o ka nalu o ke kumu kukui ʻike. No laila, ʻoi aku ka kiʻekiʻe o ke ana ʻana o nā lasers linewidth me ka hoʻokō ʻana i ka hoʻokani broadband paʻa i nā ʻōnaehana ʻike. No ka laʻana, i kekahi mau ʻōnaehana ʻike fiber optical i hoʻokaʻawale ʻia e pili ana i ka noʻonoʻo ʻana o ka optical frequency domain, pono e hoʻopau koke ʻia ka laser no ka hoʻokō ʻana i ka ʻike kikoʻī kiʻekiʻe a me ka demodulation o nā hōʻailona optical, no laila he kiʻekiʻe nā koi o ka modulation rate o ke kumu laser. , a ʻo ka māmā holo o ka laser adjustable e koi pinepine ʻia a hiki i 10 pm/μs. Eia kekahi, hiki ke hoʻohana nui ʻia ka laser linewidth haʻahaʻa haʻahaʻa haʻahaʻa haʻahaʻa i ka liDAR, ka ʻike mamao laser a me ka loiloi spectral kiʻekiʻe a me nā kahua ʻike ʻē aʻe. I mea e hoʻokō ai i nā koi o nā ʻāpana hana kiʻekiʻe o ka hoʻopaʻa ʻana i ka bandwidth, ka pololei o ke kani ʻana a me ka wikiwiki o ka hoʻopaʻa ʻana i nā lasers lōʻihi-hoʻokahi i ke kahua o ka fiber sensing, ʻo ka pahuhopu holoʻokoʻa o ke aʻo ʻana i nā lasers ākea ākea ākea i nā makahiki i hala iho nei e hoʻokō i nā kiʻekiʻe- ʻO ka hoʻokani pololei ʻana i ka laulā hawewe nui ma muli o ka hahai ʻana i ka laina laina laina haʻahaʻa haʻahaʻa haʻahaʻa, a me ke alapine puka a me ka mana.

1.3 Ke koi no ke kumu kukui laser keʻokeʻo

Ma ke kahua o ka optical sensing, kiʻekiʻe keʻokeʻo keʻokeʻo laser he mea nui e hoʻomaikaʻi i ka hana o ka ʻōnaehana. ʻOi aku ka nui o ka uhi kikoʻī o ka laser māmā keʻokeʻo, ʻoi aku ka nui o kāna noi i ka ʻōnaehana ʻike fiber optical. No ka laʻana, i ka wā e hoʻohana ai i ka fiber Bragg grating (FBG) no ke kūkulu ʻana i kahi pūnaewele sensor, hiki ke hoʻohana ʻia ka loiloi spectral a i ʻole ke ʻano hoʻohālikelike kānana hiki ke hoʻohana ʻia no ka demodulation. Ua hoʻohana ka mea mua i kahi spectrometer e hoʻāʻo pololei i kēlā me kēia FBG resonant wavelength i ka pūnaewele. Hoʻohana ka mea hope i kahi kānana kuhikuhi no ka nānā ʻana a me ka calibrate i ka FBG i ka ʻike, pono ia mau mea ʻelua i kahi kumu kukui broadband ma ke ʻano he kumu kukui hoʻāʻo no ka FBG. No ka mea e loaʻa i kēlā me kēia pūnaewele komo FBG kahi poho hoʻokomo, a loaʻa iā ia ka bandwidth o ka 0.1 nm, pono ka demodulation like o nā FBG lehulehu i kahi kumu kukui broadband me ka mana kiʻekiʻe a me ka bandwidth kiʻekiʻe. No ka laʻana, i ka wā e hoʻohana ai i ka lōʻihi fiber grating (LPFG) no ka ʻike ʻana, ʻoiai ʻo ka bandwidth o kahi kiʻekiʻe pohō hoʻokahi aia ma ke ʻano o 10 nm, kahi kumu kukui ākea ākea me ka bandwidth kūpono a me nā kikoʻī pālahalaha e koi ʻia e hōʻike pololei i kona resonant. ʻano kiʻekiʻe. ʻO ka mea nui, ʻo ka acoustic fiber grating (AIFG) i kūkulu ʻia me ka hoʻohana ʻana i ka hopena acousto-optical hiki ke hoʻokō i ka laulā o ka hawewe resonant a hiki i 1000 nm ma o ke kani uila. No laila, ʻo ka hoʻāʻo ʻana i ka hoʻāʻo ʻana me ka laulā ultra-ākea he paʻakikī nui i ka laulā bandwidth o kahi kumu kukui ākea ākea. Pēlā nō, i kēia mau makahiki i hala iho nei, ua hoʻohana nui ʻia ka tilted Bragg fiber grating i ke kula o ka fiber sensing. Ma muli o kāna mau hiʻohiʻona hiʻona nui-peak loss spectrum, hiki ke piʻi maʻamau ka laulā hawewe lōʻihi i 40 nm. ʻO ka mea maʻamau ka hoʻohālikelike ʻana i ka neʻe pili i waena o nā piko hoʻouna he nui, no laila pono ke ana ʻana i kāna kiko kikoʻī. Pono ka bandwidth a me ka mana o ke kumu kukui ākea ākea e kiʻekiʻe.

2. Ke kūlana noiʻi ma ka home a ma waho

2.1 Kumu kukui laser laulaʻi laina haiki

2.1.1 Hāʻawi ʻia ka semiconductor hōʻike manaʻo

Ma 2006, Cliche et al. ua ho'ēmi i ka pālākiō MHz o semiconductorDFB laser(laser manaʻo hāʻawi ʻia) i ka pālākiō kHz me ka hoʻohana ʻana i ke ʻano hana manaʻo uila; Ma 2011, Kessler et al. hoʻohana i ka wela haʻahaʻa a me ke kūpaʻa kiʻekiʻe o ka lua aniani hoʻokahi i hui pū ʻia me ka mana manaʻo manaʻo no ka loaʻa ʻana o ka puka laser linewidth ultra-narrow o 40 MHz; Ma 2013, ua loaʻa iā Peng et al kahi puka laser semiconductor me ka laina laina o 15 kHz ma o ka hoʻohana ʻana i ke ʻano o ka hoʻoponopono ʻana o Fabry-Perot (FP) waho. Hoʻohana nui ʻia ke ʻano manaʻo hoʻopuka uila i ka Pond-Drever-Hall frequency stabilization feedback e hoʻemi i ka laina laina laser o ke kumu kukui. Ma 2010, Bernhardi et al. i hana i 1 knm o ka erbium-doped alumina FBG ma kahi substrate silicon oxide no ka loaʻa ʻana o ka hopena laser me ka laulā laina ma kahi o 1.7 kHz. I ka makahiki hoʻokahi, Liang et al. ua hoʻohana i ka manaʻo hoʻopiʻi ponoʻī o ka hoʻopuehu ʻana o Rayleigh i hope i hoʻokumu ʻia e kahi resonator pā echo-Q kiʻekiʻe no ka hoʻopili ʻana i ka laina laina semiconductor laser, e like me ka hōʻike ʻana ma ke Kiʻi 1, a loaʻa iā ia kahi puka laser ākea laina haiki o 160 Hz.

Fig. 1 (a) Diagram of semiconductor laser linewidth compression ma muli o ka hoʻopuʻi ʻana iā ia iho ʻo Rayleigh e hoʻopuehu ana i ka resonator mode hāwanawana waho;
(b) Ke alapine alapine o ka laser semiconductor holo manuahi me ka laula laina o 8 MHz;
(c) ʻO ke alapine alapine o ka laser me ka laina laina i hoʻopaʻa ʻia i 160 Hz
2.1.2 Laser fiber laulaʻi haiki

No nā lasers fiber cavity linear, loaʻa ka puka laser linewidth haiki o ka mode longitudinal hoʻokahi ma ka pōkole o ka lōʻihi o ka resonator a me ka hoʻonui ʻana i ka manawa mode longitudinal. Ma 2004, Spiegelberg et al. loaʻa i kahi ʻano lōʻihi lōʻihi hoʻokahi laina laina laina laina me ka laina laina o 2 kHz ma o ka hoʻohana ʻana i ke ʻano DBR short cavity. Ma 2007, Shen et al. ua hoʻohana i ka 2 knm heavily erbium-doped silicon fiber no ke kākau ʻana i ka FBG ma kahi Bi-Ge co-doped photosensitive fiber, a hoʻohui ʻia me ka fiber ikaika e hana i kahi lua laina paʻa, e hoʻemi ana i ka laulā laina laser ma lalo o 1 kHz. Ma 2010, ʻo Yang et al. ua hoʻohana i ka 2cm kiʻekiʻe doped ʻaoʻao laina pōkole i hui pū ʻia me ka narrowband FBG kānana no ka loaʻa ʻana o kahi puka laser mode longitudinal hoʻokahi me ka laulā laina ma lalo o 2 kHz. Ma 2014, ua hoʻohana ka hui i kahi lua laina pōkole (virtual folded ring resonator) i hui pū ʻia me kahi kānana FBG-FP no ka loaʻa ʻana o ka hopena laser me ka laulā laina haʻahaʻa, e like me ka hōʻike ʻana ma ke Kiʻi 3. Ma 2012, Cai et al. ua hoʻohana i ka 1.4cm puʻupuʻu puʻupuʻu puʻupuʻu no ka loaʻa ʻana o ka puka laser polarizing me ka mana puka i ʻoi aku ma mua o 114 mW, kahi lōʻihi nalu waena o 1540.3 nm, a me ka laulā laina o 4.1 kHz. Ma 2013, ʻo Meng et al. hoʻohana ʻia ʻo Brillouin i ka hoʻopuehu ʻana i ka fiber erbium-doped me kahi apo pōkole o kahi hāmeʻa mālama piha-bias no ka loaʻa ʻana o kahi mode longitudinal hoʻokahi, haʻahaʻa haʻahaʻa haʻahaʻa haʻahaʻa haʻahaʻa laser me ka mana puka o 10 mW. I ka makahiki 2015, ua hoʻohana ka hui i kahi apo apo i haku ʻia me 45 knm erbium-doped fiber e like me ka Brillouin scattering gain medium no ka loaʻa ʻana o ka paepae haʻahaʻa a me ka puka laser linewidth haiki.

Fig. 2 (a) Kiʻi kiʻi kiʻi o ka laser fiber SLC;
(b) Lineshape o ka hōʻailona heterodyne i ana me 97.6 km fiber lohi