Diffraction gratings - teeb meem thiab kev daws teeb meem
1. Ib lub grating uas muaj 4000 qhov txiav ib centimeter raug ci nrog lub teeb monochromatic thiab tsim cov kab ci thib ob ntawm lub kaum sab xis 30°. Lub wavelength ntawm lub teeb siv yog dab tsi? (1 Å = 10 -10 m)
Paub:
Qhov nrug ntawm cov kab txiav (d) = 1 / (4000 kab txiav / cm) = 0.00025 cm = 2.5 x 10 -4 cm = 2.5 x 10 -6 meters
Kev txiav txim (n) = 2
Sin 30 o = 0.5
1 Å = 10 -10 m
Xav tau: Wavelength ntawm lub teeb (λ)
Tshuaj:
2. Ib lub teeb monochromatic nrog lub wavelength ntawm 2.5 × 10 -7 m ntaus ib lub grating uas muaj 10,000 slits / cm. Txheeb xyuas cov ces kaum ntawm kab ci thib ob.
Paub:
Qhov nrug ntawm cov kab txiav (d) = 1 / (10,000 kab txiav / cm) = 0.0001 cm = 1 x 10 -4 cm = 1 x 10 -6 m
Kev txiav txim (n) = 2
Qhov ntev ntawm nthwv dej (λ) = 2.5 x 10 -7 m
Xav tau: Lub kaum sab xis (θ)
Tshuaj:
3. Ib lub teeb monochromatic nrog wavelength ntawm 5.10 -7 m ntaus ib lub grating. Qhov deb ntawm qhov slit thiab lub screen saib yog 2 m, qhov deb ntawm qhov thib peb -theem ntug thiab qhov nruab nrab ntug yog 150 cm. Txheeb xyuas qhov deb ntawm cov slits.
Paub:
Qhov ntev ntawm nthwv dej (λ) = 5 x 10 -7 m
l = 2 m
n = 3
y = 150 cm = 1.5 m
Xav tau: qhov deb ntawm cov slits
Tshuaj:
sin θ ≈ tan θ = y / l = 1.5 / 2 = 0.75 = 75 x 10 -2
Nrug deb ntawm cov kab txiav:
d sin θ = n λ
d (75.10 -2 ) = (3)(5.10 -7 )
d (75.10 -2 ) = 15.10 -7
d = (15.10 -7 ) / (75.10 -2 )
d = (15/75).10 -5
d = (1/5)(10 -5 ) m
d = (0.2)(10 -5 ) m
d = 2.10 -6 m
4. Lub teeb monochromatic nrog lub wavelength ntawm 500 nm (1 nano = 10 -9 ) ntaus ib lub grating thiab tsim cov kab ci plaub theem ntawm lub kaum sab xis 30°. Txheeb xyuas tus naj npawb ntawm cov kab txiav ib centimeter.
Paub:
Qhov ntev ntawm nthwv dej (λ) = 500.10 -9 m = 5.10 -7 m
θ = 30 o
n = 4
Xav tau: tus naj npawb ntawm cov qhov txiav ib centimeter
Tshuaj:
Nrug deb ntawm cov kab txiav:
d sin θ = n λ
d (sin 30 o ) = (4)(5.10 -7 )
d (0.5) = 20.10 -7
d = (20.10 -7 ) / 0.5
d = 40.10 -7
d = 4.10 -6 m
Tus naj npawb ntawm cov qhov txiav ib centimeter:
x = 1 / 4.10 -6 m
x = 0.25.10 6 / m
x = 0.25.10 6 / 10 2 cm
x = 0.25.10 4 / cm
x = 25.10 2 / cm
x = 2500 / cm²
5. Lub teeb monochromatic nrog lub wavelength ntawm 500 nm (1 nm = 10 -9 m) ntaus ib lub grating thiab tsim cov kab ci thib ob ntawm lub kaum sab xis 30°. Txheeb xyuas tus naj npawb ntawm cov kab txiav ib centimeter.
Paub:
Qhov ntev ntawm nthwv dej (λ) = 500.10 -9 m = 5.10 -7 m
θ = 30 o
n = 2
Xav tau: tus naj npawb ntawm cov qhov txiav ib centimeter
Tshuaj:
Nrug deb ntawm cov kab txiav:
d sin θ = n λ
d (sin 30 o ) = (2)(5.10 -7 )
d (0.5) = 10.10 -7
d = (10.10 -7 ) / 0.5
d = 20.10 -7
d = 2.10 -6 m
Tus naj npawb ntawm cov qhov txiav ib centimeter:
x = 1 / hnub
x = 1 / 2.10 -6 m
x = 0.5.10 6 / 1 m
x = 0.5.10 6 / 10 2 cm
x = 0.5.10 4 / cm
x = 5.10 3 / cm
x = 5000 / cm²
20 cov lus nug thiab lus teb txog diffraction grating:
1. Lo lus nug: Lub diffraction grating yog dab tsi?
Lus Teb: Lub diffraction grating yog ib qho khoom siv kho qhov muag uas muaj cov qauv tsis tu ncua, uas faib thiab diffraction lub teeb ua ntau lub teeb uas mus ncig ua ntau qhov kev taw qhia sib txawv.
2. Lo lus nug: Diffraction grating txawv li cas ntawm ob chav slit?
Lus Teb: Txawm hais tias ob qho tib si ua rau muaj kev diffraction, lub grating muaj ntau qhov txiav (lossis kab) ib chav ntev, ua rau muaj ntau lub teeb diffraction thiab kev sib cais spectral meej dua.
3. Lo lus nug: Vim li cas qhov sib nrug ntawm cov kab grating thiaj li tseem ceeb?
Lus Teb: Qhov sib nrug txiav txim siab lub kaum sab xis uas cov wavelengths sib txawv ntawm lub teeb raug refracted, yog li cuam tshuam rau qhov kev daws teeb meem thiab qhov meej ntawm cov spectrum tsim tawm.
4. Lo lus nug: Lub kaum sab xis diffraction muaj feem cuam tshuam li cas rau qhov wavelength ntawm lub teeb?
Lus Teb: Qhov kev sib raug zoo yog muab los ntawm cov qauv grating: ��=�sin� , qhov twg yog qhov kev txiav txim ntawm diffraction, yog qhov wavelength, yog qhov sib nrug ntawm grating, thiab yog lub kaum sab xis diffraction.
6. Lo lus nug: Vim li cas cov xim sib txawv / wavelengths sib txawv ntawm cov ces kaum sib txawv?
Lus Teb: Vim tias lub kaum sab xis diffraction ( ) yog proportional ncaj qha rau qhov wavelength ( ), cov wavelengths ntev dua (xws li liab) diffract ntau dua li cov luv dua (xws li xiav).
7. Lo lus nug: Kev nce tus naj npawb ntawm cov kab txiav (lossis cov kab) hauv lub diffraction grating cuam tshuam li cas rau tus qauv?
Lus Teb: Kev nce tus naj npawb ntawm cov kab txiav ua rau qhov siab tshaj plaws ntawm diffraction ntse dua, ua kom qhov kev daws teeb meem ntawm cov spectrum zoo dua.
8. Lo lus nug: Lub zog daws teeb meem ntawm lub grating txhais li cas?
Lus Teb: Lub zog daws teeb meem yog lub peev xwm ntawm lub grating los paub qhov txawv ntawm ob lub wavelengths uas nyob sib ze. Nws nce ntxiv nrog ntau kab thiab ntau qhov kev txiav txim diffraction.
9. Lo lus nug: Cov diffraction gratings puas siv tau nrog lwm hom nthwv dej ntxiv rau lub teeb?
Lus Teb: Yog, lawv siv tau nrog txhua yam xwm txheej nthwv dej, suav nrog cov nthwv suab thiab X-rays.
10. Lo lus nug: Lub grating kis tau txawv li cas ntawm lub grating reflection?
Lus Teb: Hauv lub grating kis tau tus mob, lub teeb hla dhau cov khoom siv grating, thaum nyob rau hauv lub grating reflection, lub teeb raug cuam tshuam tawm ntawm qhov chaw grating.
11. Lo lus nug: Cov gratings blazed yog dab tsi?
Lus Teb: Cov gratings blazed yog cov gratings reflection uas cov grooves yog angled (lossis blazed) los coj feem ntau ntawm lub zog mus rau hauv ib qho kev txiav txim diffraction tshwj xeeb, optimizing efficiency.
12. Lo lus nug: Vim li cas qhov ceev ntawm qhov grating (kab ib hli) thiaj tseem ceeb?
Lus Teb: Qhov ceev ntawm qhov groove txiav txim siab qhov kev sib kis thiab kev daws teeb meem ntawm grating. Qhov ceev ntawm qhov groove siab dua feem ntau ua rau muaj kev daws teeb meem siab dua.
13. Lo lus nug: Lub grating tsim tau ib lub spectrum li cas?
Lus Teb: Thaum lub teeb dawb cuam tshuam nrog lub grating, txhua qhov wavelength difffracts ntawm ib lub kaum sab xis tshwj xeeb, nthuav lawv tawm mus rau qhov chaw kom tsim tau ib lub spectrum.
14. Lo lus nug: Vim li cas cov qib siab dua ntawm diffraction thiaj li sib tshooj nrog ib leeg?
Lus Teb: Rau cov wavelengths sib txawv, cov xaj siab dua tuaj yeem raug refracted ntawm cov ces kaum uas phim cov xaj qis dua ntawm lwm cov wavelengths, ua rau cov spectra sib tshooj.
15. Lo lus nug: Puas siv tau lub grating los kawm txog cov wavelengths uas tsis pom?
Lus Teb: Yog, cov gratings tuaj yeem tsim rau ntau qhov sib txawv ntawm cov electromagnetic spectrum, suav nrog ultraviolet thiab infrared.
16. Lo lus nug: Cov khoom siv grating ua lub luag haujlwm dab tsi hauv cov qauv diffraction?
Lus Teb: Cov khoom siv tuaj yeem cuam tshuam rau qhov ua tau zoo ntawm cov kev txiav txim diffraction sib txawv thiab txiav txim siab qhov ntau ntawm wavelength uas lub grating tau zoo tshaj plaws.
17. Lo lus nug: Yuav ua li cas thiaj tsim tau lub holographic diffraction grating?
Lus Teb: Holographic gratings yog tsim los ntawm kev siv cov qauv cuam tshuam los ntawm lub teeb laser, es tsis yog kev txiav txim siab mechanically, ua rau muaj lub teeb tsawg dua thiab cov spectra purity siab dua.
18. Lo lus nug: Vim li cas qhov siab tshaj plaws ntawm xoom feem ntau ci dua?
Lus Teb: Qhov siab tshaj plaws ntawm xoom-order sib raug rau lub teeb tsis sib xws. Vim tias nws tsis kis mus ntau npaum li cov teeb sib txawv, nws lub zog feem ntau siab dua.
19. Lo lus nug: Cov gratings puas ua haujlwm nrog lub teeb polarized?
Lus Teb: Yog, qhov ua tau zoo ntawm diffraction thiab tus qauv tuaj yeem sib txawv raws li lub xeev polarization ntawm lub teeb pom kev.
20. Lo lus nug: Vim li cas cov gratings muaj qhov zoo dua li prisms rau spectroscopy?
Lus Teb: Cov gratings tuaj yeem muab kev daws teeb meem zoo dua, kev sib kis ntawm cov wavelengths ntau dua, thiab feem ntau ua haujlwm tau zoo dua ntawm kev nthuav tawm lub teeb hla lub spectrum piv rau prisms.
Cov diffraction gratings yog qhov tseem ceeb hauv kev tshawb fawb kho qhov muag thiab daim ntawv thov, tshwj xeeb tshaj yog hauv spectroscopy, uas tso cai rau kev kawm ntxaws ntxaws ntawm lub teeb spectral Cheebtsam.
