Nyob rau hauv ib qho kev tawm mus los ntawm tus qauv modelocking mus kom ze, ib pab neeg tshawb fawb coj los ntawm cov xibfwb Giacomo Scalari thiab Jerome Fais nyob rau hauv lub Department of Physics ntawm ETH Zurich, thiab xibfwb Christian Jirauschek ntawm lub Technical University of Munich, tsim ib tug monolithic modelocked semiconductor laser nrog ib tug tsis tu ncua thiab dav tunable repetition tus nqi ntawm 4 mus rau 16 GHz. Thiab, intriguingly, lawv txoj kev yuav tsum ua hauj lwm rau lwm yam semiconductor lasers thiab laser emission wavelengths.
Txhawm rau rub nws tawm, cov kws tshawb fawb siv lub terahertz (THz) quantum cascade laser (QCL) los tsim cov coherent zaus combs. Thaum nws paub zoo tias THz QCLs tuaj yeem siv los tsim cov combs, pab pawg tsis ntev los no kev txhim kho ntawm cov phiaj xwm THz QCLs nrog kev txhim kho microwave zog txhawb kom lawv tshawb nrhiav qhov kev hloov kho muaj zog ntawm cov kab noj hniav laser siv cov microwaves sab nraud- thiab lawv nrhiav tau ntau yam tshiab ntawm kev ua haujlwm ntawm semiconductor laser.
"Peb lub cuab yeej ua raws li kev npaj THz QCL. Nws cov khoom siv hauv cheeb tsam muaj xws li gallium arsenide (GaAs) / aluminium gallium arsenide (AlGaAs) superlattice, wafer- khi rau GaAs carrier substrate," piav qhia Urban Senica, uas thaum lub sij hawm yog Ph.D. tub ntxhais kawm ntawm ETH Zurich tab sis tam sim no yog ib tus kws kho mob tom qab ntawm Harvard University's Laboratory rau Nanoscale Optics. "Los ntawm kev siv photolithography thiab qhuav etching, ib tug active ridge waveguide yog txhais thiab tom qab ntawd planarized nrog qis -tsis polymer benzocyclobutene (BCB). Ib tug waveguide yog sandwiched vertically ntawm ob ncua metallization txheej, uas kaw lub optical thiab microwave hom thiab ua raws li hluav taws xob tiv tauj rau biasing.
Txhawm rau rub nws tawm, cov kws tshawb fawb siv lub terahertz (THz) quantum cascade laser (QCL) los tsim cov coherent zaus combs. Thaum nws paub zoo tias THz QCLs tuaj yeem siv los tsim cov combs, pab pawg tsis ntev los no kev txhim kho ntawm cov phiaj xwm THz QCLs nrog kev txhim kho microwave zog txhawb kom lawv tshawb nrhiav qhov kev hloov kho muaj zog ntawm cov kab noj hniav laser siv cov microwaves sab nraud- thiab lawv nrhiav tau ntau yam tshiab ntawm kev ua haujlwm ntawm semiconductor laser.
"Peb lub cuab yeej ua raws li kev npaj THz QCL. Nws cov khoom siv hauv cheeb tsam muaj xws li gallium arsenide (GaAs) / aluminium gallium arsenide (AlGaAs) superlattice, wafer- khi rau GaAs carrier substrate," piav qhia Urban Senica, uas thaum lub sij hawm yog Ph.D. tub ntxhais kawm ntawm ETH Zurich tab sis tam sim no yog ib tus kws kho mob tom qab ntawm Harvard University's Laboratory rau Nanoscale Optics. "Los ntawm kev siv photolithography thiab qhuav etching, ib tug active ridge waveguide yog txhais thiab tom qab ntawd planarized nrog qis -tsis polymer benzocyclobutene (BCB). Ib tug waveguide yog sandwiched vertically ntawm ob ncua metallization txheej, uas kaw lub optical thiab microwave hom thiab ua raws li hluav taws xob tiv tauj rau biasing.
Kev sib txuas lus, spectroscopy, thiab daim ntawv thov kev paub ua ntej
Ua tsaug rau lawv tsis tu ncua thiab dav tunable modelocked lasers, muaj ntau yam kev siv rau kev sib txuas lus, spectroscopy, thiab sensing. Senica hais tias "Rau lub sijhawm sau npe, lub tsheb ciav hlau sib koom ua ke tuaj yeem raug synchronized mus rau qhov tsis txaus ntseeg sab nraud microwave teeb liab lossis tunable ncua kab," hais Senica. "Rau qhov ntau zaus, qhov tunable hom sib nrug nyob rau hauv qhov zaus zuag tuaj yeem kaw ib qho spectral gaps."
Qhov tseeb, Senica thiab cov npoj yaig twb tau ua kom pom qhov nqus spectroscopy qhov kev sim uas yuav tsum tau siv lub ntsuas ntsuas yooj yim nkaus xwb- tsis yog lub ntsiav tshuaj - qhov ntsuas qhov ntsuas qhov loj me.
"Peb ntseeg tias peb txoj hauv kev kuj tseem yuav ncaj qha rau kev siv nrog lwm hom semiconductor lasers thoob plaws thaj tsam infrared thiab pom ntawm electromagnetic spectrum thiab ua txoj hauv kev rau ntau yam kev siv," Senica hais. "Ib qho tseem ceeb yuav ua kom zoo dua microwave zog, nrog rau kev ntim khoom zoo li no."
