Grating, negative and replica gratings of the grating, and method of manufacturing the same

Abstract

A grating of the present invention has a groove cross section shaped, for example, like a sinusoidal wave or a sawtooth other than a laminar shape, and a groove bottom part shaped as a flat form. In a region wherein the groove cycle and the used wavelength are the same degree for wavelengths from near infrared to infrared, the grating of the present invention has the excellent spectrum performance (high efficiency in balance in a wide wavelength zone) more than a holographic grating and an echellette grating in related arts. When replicas for the grating of the present invention are manufactured, the engagement force of grooves with each other is small as the groove aspect ratio is small, and a release agent sufficiently reaches the groove bottom as the groove bottom is large.

1 . A grating having a groove cross section shape and a groove bottom part, wherein said grating is adapted for use in a wavelength range of between about 1.0-2.0 μm, the groove cross section shape is a half sinusoidal wave, and said groove bottom part is shaped as a flat form, and wherein a relationship between a groove cycle of the grating and a wavelength is such that groove cycle/wavelength <5.  
   
   
       2 . The grating as claimed in  claim 1 , wherein a duty ratio of a groove width to the groove cycle of the grating is 0.5.  
   
   
       3 . A grating having a groove cross section shape and a groove bottom part, wherein said grating is adapted for use in a wavelength range of between about 1.0-2.0 μm, said groove cross section shape is a half sawtooth wave and said groove bottom part is shaped as a flat form, and wherein a relationship between a groove cycle of the grating and a wavelength is such that groove cycle/wavelength <5.  
   
   
       4 . A replica grating manufactured by transfer from a grating having a groove cross section shape other than a laminar shape and a groove bottom part shaped as a flat form, wherein said replica grating is adapted for use in a wavelength range of between about 1.0-2.0 μm, said groove cross section shape is selected from the group consisting of a half sinusoidal wave and a half sawtooth wave, and wherein a relationship between a groove cycle of the grating and a wavelength is such that groove cycle/wavelength <5.  
   
   
       5 . The grating as claimed in  claim 3 , wherein a duty ratio of a groove width to the groove cycle of the grating is 0.5.  
   
   
       6 . The replica grating as claimed in  claim 4 , wherein a duty ratio of a groove width to the groove cycle of the grating is 0.5.