Wide band UV/Vis/NIR blazed-binary reflective gratings: two lithographic techniques investigation

Abstract

We report on subwavelength reflective gratings for hyperspectral applications operating in the 340 nm-1040 nm spectral range. The blazed grating period is 30 μm and is composed of 2D subwavelength binary structures with sizes in-between 120 nm and 350 nm. We demonstrate the manufacturing of gratings on 3” wafers by two lithography technologies (e-beam or nanoimprint) followed by dry etching process. These subwavelength gratings enable broadband efficiency which is in average 15%-20% above the efficiency requirement for next generation of spectro-imagers for Earth observation missions and a wavefront error that is much smaller than the 100 nm requirement for space application.

Imaging enhancement using multifunctional subwavelength structured windows

“…Nanoimprint lithography (NIL) is well-known for its high resolution enabling optical applications from visible to thermal infrared domains, large surface and its capability to address very dense pattern [5]. Moreover, it has also been demonstrated recently [5] that components manufactured by nanoimprint lithography combined to etching techniques introduce very low wavefront error, which is an important parameter for imaging point of view.…”

Nanoimprint-based subwavelength multifunctional optical windows: from visible to longwave infrared applications

“…In this paper, we propose the combination of nanoimprint lithography with etching processes to enable the modification of optical and fluidic properties of optical windows and we evaluate the windows performances within a MWIR Thales imaging product. Nanoimprint lithography is well-known for its high resolution enabling optical applications from visible to thermal infrared domains, large surface and its capability to address very dense patterning [5]. It has also been demonstrated recently [5] that components manufactured by nanoimprint lithography combined with etching techniques introduce very low wavefront error, which is an important parameter for imaging point of view.…”

“…Nanoimprint lithography is well-known for its high resolution enabling optical applications from visible to thermal infrared domains, large surface and its capability to address very dense patterning [5]. It has also been demonstrated recently [5] that components manufactured by nanoimprint lithography combined with etching techniques introduce very low wavefront error, which is an important parameter for imaging point of view. We demonstrate the use of nanoimprint technology pushed at the micro-nanoscale for patterning large surfaces, up to 3" windows, composed of high-density subwavelength geometries.…”