Optical devices having transmission enhanced by surface plasmon mode resonance, and their use in data recording
View Patent ↗A device includes an optical gain medium through which optical radiation is amplified. The device includes first and second reflectors disposed around the gain medium. One of the reflectors includes an emission region though which optical output is emitted and a metallic structure that has an array of features that couple the radiation to at least one surface plasmon mode of the structure, thereby enhancing the device's output. The device may be a laser, e.g., a diode laser. The emission region may have a width of, for example, between 10 and 100 nanometers, and this emission region may be in the shape of a rectangular slit. The optical radiation in the gain medium may be advantageously polarized perpendicularly to an axis along which a longer dimension of the emission region is oriented. The device is useful for data recording, e.g., thermally assisted data recording.
1. A device, comprising:
an optical gain medium through which optical radiation is amplified; and
a first reflector and a second reflector disposed around said gain medium, wherein one of said reflectors includes:
at least one emission region though which optical output is emitted, wherein said emission region has a cross section having at least one dimension no greater than an average wavelength of the optical output; and
a metallic structure having an array of features that couple the radiation to at least one surface plasmon mode of said structure to increase the emitted optical output from said emission region beyond what the emitted optical output from said emission region would be in the absence of said features.
2. The device of claim 1 , wherein said emission region has a width of between 10 and 100 nanometers.
3. The device of claim 1 , wherein said emission region has a width of between 10 and 50 nanometers.
4. The device of claim 1 , wherein the optical radiation in said gain medium is polarized perpendicularly to an axis along which a longer dimension of said emission region is oriented.
5. The device of claim 1 , wherein said emission region includes a rectangular slit.
6. The device of claim 1 , wherein the spacing between said features in said array is chosen to resonantly enhance the optical output from said emission region at at least one predetermined frequency.
7. The device of claim 1 , wherein said optical gain medium, said first reflector, and said second reflector form a laser.
8. The device of claim 1 , wherein said optical gain medium includes:
a layer of n-type semiconductor material;
a layer of p-type semiconductor material; and
an active layer from which photons are emitted, said active layer positioned between said n-type layer and said p-type layer.
9. The device of claim 1 , wherein the optical output includes light in the visible portion of the spectrum.
10. The device of claim 1 , said features comprising ridges within said metallic structure.
11. The device of claim 10 , further comprising dielectric material in contact with said features.
12. The device of claim 1 , wherein said metallic structure includes at least one of Au, Ag, Al, Cr, and Cu.
13. A device, comprising:
an optical gain medium through which optical radiation is amplified; and
a first reflector and a second reflector disposed around said gain medium, wherein one of said reflectors includes:
at least one emission region though which optical output is emitted, wherein said emission region has a cross section having at least one dimension no greater than an average wavelength of the optical output; and
a metallic structure having an array of features that couple the radiation from one side of said structure to another side of said structure through surface plasmons generated in said structure by the optical radiation, wherein said emission region includes a slit, and the optical radiation in said gain medium is polarized perpendicularly to an axis along which a longer dimension of said slit is oriented.
14. The device of claim 13 , wherein said optical gain medium, said first reflector, and said second reflector form a laser.
15. The device of claim 13 , wherein said laser comprises a diode laser.
16. The device of claim 13 , wherein said metallic structure includes at least one of Au, Ag, Al, Cr, and Cu.
17. The device of claim 13 , wherein the spacing between said features in said array is chosen to enhance the optical output from said emission region at at least one predetermined frequency.
18. The device of claim 13 , wherein said emission region includes a rectangular slit.
19. The device of claim 18 , wherein said slit has a width of between 10 and 100 nanometers.
20. A device, comprising:
an optical gain medium through which optical radiation is amplified; and
a first reflector and a second reflector disposed around said gain medium, wherein one of said reflectors includes:
at least one emission region though which optical output is emitted, wherein said emission region has a cross section having a longer dimension that is no greater than an average wavelength of the optical output and a shorter dimension of between 10 and 100 nanometers; and
a metallic structure having an array of features that couple the radiation from one side of said structure to another side of said structure through surface plasmons generated in said structure by the optical radiation, wherein the spacing between said features in said array is chosen to resonantly enhance the optical output from said emission region at at least one predetermined frequency, and the optical radiation in said gain medium is polarized perpendicularly to an axis along which the longer dimension of said emission region is oriented.