Lamellar grating structure with polarization-independent diffraction efficiency
AssigneeChromaplex, Inc.
InventorsJohn Hoose, Robert Frankel, Evgeny Popov
Life of this patent
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Abstract
A lamellar volume grating operating in reflection and transmission and providing a substantially wavelength- and polarization-independent diffraction efficiency is disclosed. The lamellar grating has an approximately rectangular grating profile with a height-to-width ratio of the grooves or “teeth” advantageously greater than 2. The grating operates preferably in first order and can be implemented as an immersion grating. In particular, the lamellar volume grating described herein can be employed in an optical multiplexer/demultiplexer arrangement with small overall dimensions.
Claims26
A grating device comprising:
- a volume grating produced in a free surface of a substrate and having a grating period,
- the grating period comprising a first region having a first refractive index of the substrate and a second region having a second refractive index different from the first refractive index, and
- an optically transparent element contacting the free surface of the material which includes the volume grating.
A wavelength-dispersive element comprising:
- a first prism having an entrance face and a first contact face;
- a second prism having an exit face and a second contact face;
- a grating disposed between the first contact face and the second contact face;
- wherein optical radiation impinging on the entrance face is diffracted by the grating towards the exit face with a diffraction efficiency that is substantially independent of the polarization direction of the impinging optical radiation over a predetermined wavelength range.
Optical multiplexing/demultiplexing connector comprising:
- an input port adapted to receive optical radiation having a plurality of input wavelengths;
- an exit port adapted to transmit at least one of the plurality of input wavelengths;
- a prism having an entrance face and an exit face, and receiving the optical radiation from the input port at an input angle substantially normal to the entrance face;
- and
- a volume grating disposed within the prism intermediate between the entrance face and the exit face and diffracting the received optical radiation with a diffraction order no higher than first order towards the exit face of the prism, wherein the diffracted radiation exits the exit face of the prism at an exit angle substantially normal to the exit face towards the exit port.
A method of manufacturing a wavelength-dispersive grating element, comprising:
- producing a grating structure on a contact surface of a first prism;
- and
- bonding a contact surface of a second prism to the grating structure.
Dependencies are inferred from the claim text.