Monolithic dual-grating phase mask for long grating writing

Yannick Bourgin (1) , Sanaa Bakkali (1) , Yves Jourlin (1) , Svetlen Tonchev (1, 2) , Olivier Parriaux (1)

1 LHC - Laboratoire Hubert Curien
2 ISSP - Institut of the Solid State Physics

A new type of achromatic phase mask is presented which creates an interferogram of single spatial frequency regardless of the ratio between the interferogram period and the exposure wavelength. The functional demonstration of this monolithic phase mask was made in the case of a long grating of period as large as 2 µm by mean of an exposure beam at 442 nm wavelength, i.e., more than four times smaller. The monolithic element performs one first splitting function exerted by a central transmission grating of period 1 which diffracts the incoming beam in two diffracted beams in the substrate which are then reflected to the backside of the substrate. The element performs a second diffractive function by means of two identical side-grating of period 2 placed at either side of the first grating. This function is the redirection of the two said beams under the monolith substrate at an angle which creates an interferogram of the desired period

Mots clés: Micro-optic; diffraction gratings; monolithic phase mask; optical lithography

Domaines: Optique / photonique

Yannick Bourgin, Sanaa Bakkali, Yves Jourlin, Svetlen Tonchev, Olivier Parriaux. Monolithic dual-grating phase mask for long grating writing. SPIE Photonics Europe 2010, Apr 2010, Brussels, Belgium. pp.7716-57. ⟨ujm-00476947⟩