Photodetector Series: Introduction to Balance Photodetector

Hoʻolauna iMea ʻike kiʻi kaulike(Optoelectronic Balance Detector)
Hiki ke hoʻokaʻawale ʻia ʻo Balance Photodetector i ke ʻano o ka hoʻopili ʻana i ka fiber optic a me ke ʻano o ka hoʻopili ʻana i ka spatial optical coupling type e like me ke ʻano hoʻohui optical. Ma loko, aia i loko o ʻelua photodiodes i hoʻohālikelike ʻia, kahi haʻahaʻa haʻahaʻa, kiʻekiʻe bandwidth transimpedance amplifier circuit module, a me kahi module mana leo haʻahaʻa haʻahaʻa. Loaʻa iā ia nā hiʻohiʻona o ka ratio rejection mode maʻamau, ultra-low noise, a me ka bandwidth kiʻekiʻe, a hoʻohana nui ʻia i ke kahua o ka kamaʻilio optical coherent. Ua lilo ia i wahi hotspot noiʻi no nā ʻoihana a me nā kulanui ma nā ʻāina like ʻole i nā makahiki i hala.
Ke kumu hana o Balance Photodetector (Optoelectronic Balance Detector)
Hoʻohana ka Balance Photodetector i ʻelua photodiodes ma ke ʻano hoʻohālikelike ʻē aʻe ma ke ʻano he ʻāpana lawe kukui. I ka loaʻa ʻana o kahi hōʻailona māmā, e unuhi ʻia ke kiʻi kiʻi i hana ʻia e nā photodiodes ʻelua a hoʻohui ʻia i kahi amplifier transimpedance e hoʻohuli i ka hōʻailona o kēia manawa i hōʻailona uila no ka hoʻopuka. Hiki i ka hoʻohana ʻana i ka hoʻohaʻahaʻa ponoʻī ke hoʻopau i ka hōʻailona mode maʻamau i hoʻokomo ʻia e ka oscillator kūloko a me ka pōʻeleʻele o kēia manawa, e hoʻonui i ka hōʻailona mode differential, a i kekahi manawa hoʻomaikaʻi i ka hiki ke ʻike i nā hōʻailona māmā nāwaliwali.
Pōmaikaʻi: Hiki ke hoʻokō i nā hiʻohiʻona noiʻi kiʻekiʻe, ka ʻike kiʻekiʻe, a me ka bandwidth ʻike kiʻekiʻe.
Nā hemahema: ʻO ka mana optical saturated haʻahaʻa, kūpono wale no ka ʻike māmā nāwaliwali, pono e hoʻomaikaʻi ʻia ka hoʻohui.

FIG: Kiʻikuhi kumu hana o ka ʻike kaulike
Nā palena hana o Balance Photodetector (OptoelectronicʻIke Kaulike)
1. Pane
ʻO ka pane e pili ana i ka pono o kahi photodiode i ka hoʻohuli ʻana i nā hōʻailona māmā i photocurrent, ʻo ia ka ratio o ka photocurrent i ka mana māmā. ʻO ke koho ʻana i kahi photodiode me ke kuleana kiʻekiʻe e hiki ke hoʻomaikaʻi maikaʻi i ka naʻau o ka Balance Photodetector.
ʻO ka pane e pili ana i ka pono o kahi photodiode i ka hoʻohuli ʻana i nā hōʻailona māmā i photocurrent, ʻo ia ka ratio o ka photocurrent i ka mana māmā. ʻO ke koho ʻana i kahi photodiode me ke kuleana kiʻekiʻe e hiki ke hoʻomaikaʻi maikaʻi i ka naʻau o ka Balance Photodetector.
2. Bandwidth
Hōʻike ka bandwidth i ka alapine hōʻailona kahi e hoʻopau ai ka amplitude hōʻailona o ka Balance Photodetector e -3dB, a pili i ka capacitance parasitic o ka photodiode, ka nui o ka transimpedance, a me ka loaʻa ʻana o ka huahana bandwidth o ka amplifier hana.
3. Lakiō hōʻole ʻano maʻamau
Hoʻohana ʻia ka lakio hōʻole ʻano maʻamau no ke ana ʻana i ke kiʻekiʻe o ka hoʻopaʻa ʻana i nā hōʻailona mode maʻamau e nā mea ʻike kaulike, a ʻo nā huahana pāʻoihana maʻamau e koi aku i kahi haʻahaʻa haʻahaʻa maʻamau o 25dB.
4.NEP
Mana Kaulike Noise: ʻO ka mana hōʻailona hoʻokomo i koi ʻia ma ka ratio signal-to-noise o 1, he mea nui ia no ke ana ʻana i ka hana leo o kahi ʻōnaehana. ʻO nā mea nui o ka walaʻau ʻike kaulike ʻo ia ka leo hoʻopuehu optical a me ka walaʻau uila.

Hoʻohana i ka ʻike kiʻi kaulike (Optoelectronic Balance Detector)
I nā makahiki i hala iho nei, ua hoʻohana nui ʻia ka Balance Photodetector i nā kula e like me ka laser wind radar, laser vibration ana, fiber optic sensing, nāwaliwali māmā coherent detection, spectral detection, gas detection, etc.