Indlela yokunciphisa ingxolo yeefotodetectors

Indlela yokunciphisa ingxolo yeefotodetectors

Ingxolo photodetectors ikakhulu ibandakanya: ingxolo yangoku, ingxolo thermal, ingxolo shot, 1/f ingxolo kunye ingxolo wideband, njl. Ngeli xesha, siza kwazisa ngakumbi iimpawu zengxolo kunye nokuhlelwa ukunceda wonke umntu aqonde ngcono ifuthe leentlobo ezahlukeneyo zengxolo kwiimpawu eziphumayo zeefotodetectors. Kuphela ngokuqonda imithombo yengxolo sinokunciphisa ngcono kwaye siphucule ingxolo yeefotodetectors, ngaloo ndlela siphucula umlinganiselo wesignali-kwingxolo yenkqubo.

Ingxolo yokudutyulwa kukuguquguquka okungacwangciswanga okubangelwa yindalo ecacileyo yabathwali bentlawulo. Ngokukodwa kwimpembelelo ye-photoelectric, xa iifotoni zibetha amacandelo e-photosensitive ukuvelisa ii-electron, ukuveliswa kwezi electron akukhethi kwaye kuhambelana nokuhanjiswa kwePoisson. Iimpawu ezibonakalayo zengxolo yokudutyulwa zisicaba kwaye azixhomekekanga kubungakanani befrikhwensi, kwaye ke ikwabizwa ngokuba yingxolo emhlophe. Inkcazo yemathematika: Ingcambu yentsingiselo yesikwere (RMS) ixabiso lengxolo yokudutyulwa ingabonakaliswa ngolu hlobo:

Phakathi kwabo:

e: Intlawulo ye-elektroniki (malunga ne-1.6 × 10-19 coulombs)

Idark: Kumnyama ngoku

Δf: Ubungakanani boluhlu

Ingxolo yokudubula ilingana nobukhulu bangoku kwaye izinzile kuzo zonke iifrikhwensi. Kwifomula, i-Idark imele umbane omnyama we-photodiode. Oko kukuthi, ngokungabikho kokukhanya, i-photodiode inengxolo engafunekiyo yangoku emnyama. Njengoko ingxolo yendalo kwisiphelo sangaphambili se-photodetector, inkulu i-current emnyama, inkulu ingxolo ye-photodetector. Umsinga omnyama ukwachatshazelwa yivoltheji yokusebenza ye-bias ye-photodiode, oko kukuthi, ubukhulu bombane osebenzayo we-bias, ngakumbi umbane obumnyama. Nangona kunjalo, i-voltage esebenzayo ye-bias ichaphazela i-junction capacitance ye-photodetector, ngaloo ndlela ibe nefuthe kwisantya kunye ne-bandwidth ye-photodetector. Ngaphezu koko, i-voltage enkulu ye-bias, isantya esikhulu kunye ne-bandwidth. Ke ngoko, ngokubhekiselele kwingxolo yokudubula, ubumnyama bangoku kunye nokusebenza kwe-bandwidth yeefotodiodes, uyilo olufanelekileyo kufuneka lwenziwe ngokweemfuno zeprojekthi.

2. 1/f Ingxolo yeFlicker

Ingxolo eyi-1/f, ekwaziwa ngokuba yingxolo ephaphazelayo, iyenzeka ikakhulu kuluhlu lwefrikhwensi ephantsi kwaye inxulumene nezinto ezifana neziphene zempahla okanye ukucoceka komphezulu. Ukusuka kwidayagram yeempawu ze-spectral, kunokubonwa ukuba ubuninzi bayo bokuxinana kwamandla buncinci kakhulu kuluhlu lwe-frequency ephezulu kunoluhlu lwe-frequency ephantsi, kwaye kuwo onke amaxesha e-100 anyuka ngokuphindaphindiweyo, ingxolo ye-spectral density iyancipha ngokuthe ngqo ngamaxesha angama-10. Uxinaniso lwamandla okubonwa kwengxolo ye-1/f ihambelana ngokuphambeneyo nefrequency, oko kukuthi:

Phakathi kwabo:

SI(f) : Ubuninzi bembonakalo yamandla engxolo

Mna: Ngoku

f: Ukuphindaphinda

Ingxolo ye-1/f ibalulekile kuluhlu lwe-frequency ephantsi kwaye iyancipha njengoko i-frequency inyuka. Olu phawu luyenza ibe ngumthombo omkhulu wokuphazamiseka kwizicelo ezisezantsi-frequency. I-1/f ingxolo kunye ne-wideband ingxolo ivela ikakhulu kwingxolo yombane we-amplifier yokusebenza ngaphakathi kwe-photodetector. Kukho eminye imithombo yengxolo echaphazela ingxolo ye-photodetectors, njengengxolo yokunikezelwa kwamandla e-amplifiers esebenzayo, ingxolo yangoku, kunye nesandi esishushu somnatha wokumelana nokuzuza kweesekethe ze-amplifier zokusebenza.

3. I-voltage kunye nengxolo yangoku ye-amplifier yokusebenza: I-voltage kunye ne-spectral densities yangoku iboniswe kulo mfanekiso ulandelayo:

Kwiisekethe ze-amplifier ezisebenzayo, ingxolo yangoku ihlulwe kwi-in-phase current ingxolo kunye ne-inverting current ingxolo. Ingxolo yangoku yenqanaba i+ iqukuqela kumthombo wokuchasana kwangaphakathi kwe-Rs, ivelisa ingxolo yombane olinganayo u1= i+*Rs. I-Inverting ingxolo yangoku ihamba ngokufumana i-resistor elinganayo ye-R ukuvelisa ingxolo ye-voltage elinganayo u2 = I-* R. Ngoko xa i-RS yonikezelo lwamandla inkulu, ingxolo yombane eguqulwayo kwingxolo yangoku nayo inkulu kakhulu. Ke ngoko, ukulungiselela ingxolo engcono, ingxolo yonikezelo lwamandla (kubandakanywa nokuchasana kwangaphakathi) ikwayindlela ephambili yokuphucula. Ubuninzi bembonakalo yengxolo yangoku ayitshintshi kunye nokwahluka kwamaza. Ke ngoko, emva kokunyuswa yisekethe, yona, njengombane omnyama wefotodiode, ibumba ngokubanzi ingxolo yokudubula kwefotodetector.

4. Ingxolo ye-thermal yenethiwekhi yokumelana nenzuzo (i-amplification factor) yesekethe ye-amplifier yokusebenza ingabalwa ngokusebenzisa le fomula ilandelayo:

Phakathi kwabo:

k: IBoltzmann rhoqo (1.38 × 10-23J/K)

T: Ubushushu obupheleleyo (K)

R: Ukumelana (i-ohms) ingxolo ye-thermal ihambelana neqondo lokushisa kunye nexabiso lokumelana, kwaye i-spectrum yayo i-flat. Inokubonwa kwifomula ukuba inkulu ixabiso lokumelana nokufumana, kokukhona ingxolo ye-thermal. Ubukhulu be-bandwidth, inkulu ingxolo ye-thermal iya kuba nayo. Ngoko ke, ukuqinisekisa ukuba ixabiso lokuchasana kunye nexabiso le-bandwidth lihlangabezana neemfuno zokuzuza kunye neemfuno ze-bandwidth, kwaye ekugqibeleni zifuna ingxolo ephantsi okanye i-signal-to-noise ratio, ukukhethwa kwee-resistors zokufumana inzuzo kufuneka kuqwalaselwe ngononophelo kwaye kuvavanywe ngokusekelwe kwiimfuno zangempela zeprojekthi ukufezekisa umlinganiselo ofanelekileyo wesignali-kwingxolo yenkqubo.

Isishwankathelo

Itekhnoloji yokuphucula ingxolo idlala indima ebalulekileyo ekwandiseni ukusebenza kweefotodetectors kunye nezixhobo zombane. Ukuchaneka okuphezulu kuthetha ingxolo ephantsi. Njengoko itekhnoloji ifuna ukuchaneka okuphezulu, iimfuno zengxolo, umlinganiso wesignali ukuya kwingxolo, kunye namandla alinganayo engxolo eefotodetectors nazo ziya zinyuka ngokunyuka.