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.

Abstract: A substrate is subjected to holographic exposure to a sinusoidal or half-sinusoidal resist pattern corresponding to grating groove thereon. Thereafter, the substrate and the resist pattern are subjected to a first etching step at which they are irradiated with an ion beam obliquely at an angle that is identical to the blaze angle in the presence of CF4 as an etching gas, whereby they are cut until the height of the resist is about ? of the initial value. Thereafter, the substrate is subjected to a second etching step at which the substrate is irradiated with an ion beam in the direction corresponding to the bisector of the vertex in the presence of a mixture of CF4 and O2 as an etching gas, whereby the substrate is cut until the resist disappears completely to an extent such that some overetching occurs.

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.

Abstract: In a method of forming a holographic grating, a photoresist layer is formed on an optical substrate, and a resist pattern is formed in the photoresist layer to have grooves depth deeper than a predetermined depth of diffraction grating grooves to be formed. Then, the photoresist layer with the resist pattern is etched by an ion beam generated by a mixed gas containing a fluorine based gas and oxygen until the resist pattern is substantially completely disappears. Thus, the diffraction grating grooves having the predetermined depth are directly engraved on the optical glass plate.

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.

Abstract: In producing an etalon, a thickness of an etalon base plate is measured, and the etalon base plate is placed in a process chamber. Then, a gas having a chemical reactivity with respect to a material of the etalon base plate is introduced into the process chamber, and a surface of the etalon base plate is etched for only a predetermined time corresponding to a thickness of the etalon base plate, thereby obtaining the etalon having a desired thickness.

Abstract: A substrate is subjected to holographic exposure to a sinusoidal or half-sinusoidal resist pattern corresponding to grating groove thereon. Thereafter, the substrate and the resist pattern are subjected to a first etching step at which they are irradiated with an ion beam obliquely at an angle that is identical to the blaze angle in the presence of CF4 as an etching gas, whereby they are cut until the height of the resist is about ? of the initial value. Thereafter, the substrate is subjected to a second etching step at which the substrate is irradiated with an ion beam in the direction corresponding to the bisector of the vertex in the presence of a mixture of CF4 and O2 as an etching gas, whereby the substrate is cut until the resist disappears completely to an extent such that some overetching occurs.

Abstract: In a method of forming a holographic grating, a photoresist layer is formed on an optical substrate, and a resist pattern is formed in the photoresist layer to have grooves depth deeper than a predetermined depth of diffraction grating grooves to be formed. Then, the photoresist layer with the resist pattern is etched by an ion beam generated by a mixed gas containing a fluorine based gas and oxygen until the resist pattern is substantially completely disappears. Thus, the diffraction grating grooves having the predetermined depth are directly engraved on the optical glass plate.

Abstract: In producing an etalon, a thickness of an etalon base plate is measured, and the etalon base plate is placed in a process chamber. Then, a gas having a chemical reactivity with respect to a material of the etalon base plate is introduced into the process chamber, and a surface of the etalon base plate is etched for only a predetermined time corresponding to a thickness of the etalon base plate, thereby obtaining the etalon having a desired thickness.

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.

Abstract: In order to form a holographic grating of the invention, a resist pattern having a groove depth deeper than a desired depth of diffraction grating grooves is engraved in a photoresist layer provided on an optical glass base plate by an exposure method. Then, the photoresist layer is etched by an ion beam generated by a mixed gas containing a fluorine based gas and oxygen until the photoresist layer is completely deleted. In etching the photoresist layer, the ion beam is irradiated from a direction, which is perpendicular to a grooving direction of the resist pattern and is inclined from a normal line direction of the base plate. As a result, there can be formed the holographic grating in which the diffraction grating grooves are directly engraved in the optical glass base plate. Since the diffraction grating grooves are directly engraved in the optical base plate, the photoresist layer is not peeled off as in the conventional grating, and the holographic grating of the invention has excellent durability.

Abstract: The present invention discloses diffraction gratings which do not generate any thermal strain and can perform extremely high-precision and high-efficiency diffraction nearly free from scattered beams. The diffraction gratings are built by allowing the chemically deposited film of silicon carbide whose crystal planes are strongly oriented to the (220) planes in terms of Miller indices to form on the substrate comprising sintered silicon carbide, polishing the surface of the deposited film to 5 .ANG. RMS or less, and directly etched laminar-type grating grooves on that surface by using ion-beam etching.

Abstract: A dry etching method for etching a surface of a substrate with plasma of mixed gas including i) gas that is reactive to the material of the substrate, and ii) inert gas. Accumulation of reaction products between the substrate and the reactive gas ions on the substrate is effectively eliminated by the ions of the inert gas plasma. Accordingly the etching rate of the substrate is not lowered. Silicon carbide (SiC) is one of the most suitable object of the plasma etching of the present invention, since it is hard to engrave by conventional dry etching methods.