Patent ID: 9045933
Filing Date: 2015-06-02
Classification: E06B,G02B

Abstract:
1. A method of spatially separating visible and near-infrared electromagnetic radiation, the method comprising the steps of: providing a first blazed diffraction grating, said first blazed diffraction grating having a first blaze direction, a first grating pitch and a first blaze angle; providing a second blazed diffraction grating positioned in optical communication with said first blazed diffraction grating, said second blazed diffraction grating having a second blaze direction, a second grating pitch and a second blaze angle, and wherein said first grating pitch and said second grating pitch are different, wherein said first blaze angle and said second blaze angle are different and wherein said second blaze direction is oriented opposite to said first blaze direction; passing visible electromagnetic radiation and near-infrared electromagnetic radiation through said first blazed diffraction grating, wherein at least a portion of said visible electromagnetic radiation is diffracted by said first blazed diffraction grating in a first diffraction direction and a majority of said near-infrared electromagnetic radiation is not diffracted by said first blazed diffraction grating, thereby generating diffracted visible electromagnetic radiation and non-diffracted near-infrared electromagnetic radiation; passing said diffracted visible electromagnetic radiation and said non-diffracted near-infrared electromagnetic radiation through said second blazed diffraction grating, wherein at least a portion of said non-diffracted near-infrared electromagnetic radiation is diffracted by said second blazed diffraction grating in a second diffraction direction, thereby generating diffracted near-infrared electromagnetic radiation; wherein said first diffraction direction is different from said second diffraction direction, thereby spatially separating said visible electromagnetic radiation and said near-infrared electromagnetic radiation.