Point diffraction interferometer

Usoro PDI bụ ngwá ọrụ bara uru iji tụọ njirimara zuru oke nke ihe anya ma ọ bụ ihe na-egbuke egbuke n'ụzọ na-adịghị emebi emebi. Nhazi ụzọ a na-ahụkarị na-ewepụ mkpa ọ bụla nke inwe ihe nyocha, nke a maara na ọ na-ekpuchi ụdị elu zuru oke nke ihe nnwale na njehie ọdịdị elu ya. Nke a bụ nnukwu nsogbu nke usoro ụzọ abụọ, dị ka Fizeau interferometers, dịka egosiri na Foto 2. 'otu aka ahụ, usoro ụzọ a na-ahụkarị na-eguzogide nsogbu gburugburu ebe obibi. 

Isi nkatọ nke imewe mbụ ahụ bụ (1) na nnyefe dị ala achọrọ na-ebelata arụmọrụ, na (2) mgbe ụzarị ahụ na-aghọ ihe na-adịghị mma, a na-ebelatara ike na axis, na obere ìhè dị maka ụzarị ntụaka, na-eduga na mfu nke ọdịiche dị n'akụkụ. A na-ejikọta nnyefe dị ala na ọnụ ọgụgụ dị ala nke mgbaàmà na mkpọtụ. A na-emeri nsogbu ndị a n'ụzọ dị ukwuu na nhazi interferometer nke na-agbanwe agbanwe, nke a na-emepụta ọtụtụ, otu ụdị nke beam nke na-eme na ihe mkpuchi opaque. Igwe nnwale ahụ na-agafe n'ime oghere buru ibu ma ọ bụ oghere dị na membrane, na-enweghị mfu n'ihi ịmịkọrọ; a na-elekwasị anya na oghere maka nnyefe kachasị elu. N'ihe atụ nke dabeere na grating, a na-eme mgbanwe nke oge site na ịsụgharị grating na-aga n'ihu na mkpebi, ebe a na-edekọ ọtụtụ ihe oyiyi. Ọganihu -aga n'ihu na PDI na-agbanwe agbanwe emeela ka usoro ziri ezi dị ukwuu karịa usoro Fizeau.

ẞE mepụtara nsụgharị mgbanwe nke [lee Interferometry] iji bulie mkpebi na arụmọrụ. Ndị  gụnyere interferometer diffraction grating site na Kwon  na Phase-Shifting Point Diffraction Interferometer.

## Ụdị usoro PDI na-agbanwe agbanwe

### PDI na-agbanwe agbanwe na otu pinhole
Gary Sommargren  chepụtara atụmatụ interferometer nke na-esote kpọmkwem site na nhazi bụ isi ebe a na-eji akụkụ nke ọdịda anyanwụ eme ihe maka nnwale na akụkụ fọdụrụnụ maka nchọpụta dị ka egosiri na Foto 3. Nhazi a bụ nnukwu mmelite na usoro ndị dị ugbu a. Atụmatụ ahụ nwere ike ịlele elu anya n'ụzọ ziri ezi na mgbanwe nke 1 nm. &nbsp; na-enweta mgbanwe nke oge site na ịkwaga akụkụ nnwale ahụ na piezo eletrik translation stage. Mmetụta na-achọghị nke ịkwaga akụkụ ule ahụ bụ na defocus na-agagharị na-agbagọ akụkụ ahụ. Ihe ọzọ na-adịghị mma nke usoro Sommargren bụ na ọ na-emepụta obere ọdịiche dị iche iche  na mgbalị ịchịkwa ọdịiche ahụ na-agbanwekwa ihu ihu igwe a tụrụ.

### Usoro PDI na-eji eriri anya
N'ụdị ntụpọ diffraction interferometer a, isi iyi bụ otu eriri. A na-eme ka ihu ikpeazụ dị warara iji yie cone ma kpuchie ya na fim ígwè iji belata ọkụ. A na-ahazi eriri ka ha wee mepụta ebili mmiri dị gburugburu maka nyocha na ntinye aka. A maara njedebe nke eriri anya ka ọ na-emepụta ebili mmiri dị gburugburu nke ziri ezi karịa 

N'afọ 2000 

{\displaystyle \lambda \diagup 2000} 

. Ọ bụ ezie na PDIs dabeere na eriri anya na-enye ọganihu ụfọdụ karịa usoro pinhole, ọ na-esiri ha ike ịmepụta ma jikọta ha.
alt=Phase Shifting Point Diffraction Interferometer|áká_ịkẹngạ|thumb|264x264px|Ihe osise 4: Interferometer nke na-agbanwe agbanwe nke abụọ, ebe enwere ike ịchịkwa ụzarị ntụziaka n'onwe ya maka mgbanwe nke oge na nhazi ọdịiche.

### PDI na-agbanwe agbanwe nke abụọ
PDI-beam abụọ na-enye nnukwu uru karịa atụmatụ ndị ọzọ site n'ịkwalite ọkụ abụọ nwere onwe ha.  N'ebe a, nlele ule na ntụgharị ntụaka na-adabere na ibe ha, ebe enwere ike ịhazi ike nke ntụaka.  N'otu aka ahụ, enwere ike nweta mgbanwe oge na-adịghị mma na nke kwụsiri ike n'ihe gbasara ihie ule na-edobe akụkụ ule ahụ kwụ ọtọ.  Atụmatụ ahụ dị ka egosiri na eserese 4 dị mfe imepụta ma na-enye ọnọdụ nha nke enyi na enyi dịka Fizeau ụdị interferometers.  N'otu oge ahụ na-enye uru ndị ọzọ:

# Ụdị elu zuru oke nke akụkụ ule ahụ.
# Ọnụ ọgụgụ dị elu (NA = 0.55).
# Ihe ngosi doro anya nke ọdịiche dị elu.
# Eziokwu dị elu nke nnwale ọdịdị elu (mmegide RMS 0.125 nm).&nbsp;
# Ugboro RMS n'ihu 0.05 nm.&nbsp;
# Enwere ike ịlele akụkụ nyocha nke depolarising.

Ngwaọrụ ahụ na-ezo aka n'onwe ya, ya mere enwere ike iji ya mee ihe na gburugburu ebe obibi nwere ọtụtụ ịma jijiji ma ọ bụ mgbe enweghị ntụle, dịka n'ọtụtụ ihe ngosi na-agbanwe agbanwe na ihe omume dị mkpirikpi.
alt=Absolute surface form obtained by phase-shifting interferometry using an industrial point diffraction interferometer manufactured by Difrotec.|áká_ịkẹngạ|thumb|254x254px|Ụdị elu zuru oke nke a nwetara site na interferometry na-agbanwe agbanwe site na iji interferometer diffraction nke Difrotec rụrụ

### Ntinye nke PDI
A na-eji interferometry mee ihe maka njirimara ọnụọgụ dị iche iche nke sistemu anya na-egosi arụmọrụ ha n'ozuzu ya.  Na omenala, ejirila Fizeau interferometers chọpụta ụdị elu anya ma ọ bụ na-egbu maramara mana ọganihu ọhụrụ na nrụpụta nkenke ekwela ka interferometry dị iche iche nke ụlọ ọrụ nwee ike.  PDI dabara nke ọma maka mkpebi dị elu, nha ziri ezi dị elu na ọnọdụ ụlọ nyocha ruo ala ụlọ nrụpụta mkpọtụ.  Enweghị ihe nrụtụ aka na-eme ka usoro ahụ dabara adaba iji anya nke uche hụ ụdị sistemu ngwa anya zuru oke.  Ya mere, PDI dabara n'ụzọ pụrụ iche iji nyochaa nyocha nyocha nke interferometers ndị ọzọ.  Ọ na-abakwa uru nke ukwuu n'ịtụle mgbakọ anya nke ejiri na sistemụ dabere na Laser.  Na-egosipụta ngwa anya maka UV lithography.  Njikwa ogo nke ngwa anya ziri ezi.  Na-enyocha mkpebi n'ezie nke mgbakọ anya.  Na-atụ maapụ ihu ebili mmiri nke X-ray optics mepụtara.  PS-PDI nwekwara ike iji nyochaa mkpebi nke oghere oghere tupu ebuga ya.

## Hụkwa

* Interferometry

## Ihe odide