Laser diode for heat-assisted magnetic recording, and related apparatuses, devices, systems, and methods
Laser diodes that include a mirror stack on the light-exit facet. The mirror stack has a reflectivity into the active region that is greater in air than when the laser diode is integrated into an apparatus. Related apparatuses, data storage devices, computing systems, and methods.
1 . A laser diode comprising:
a body of one or more non-self-supporting layers of crystalline material, wherein the body has a light-exit facet at an end of the body, and wherein the body comprises an active region of the laser diode; and
a mirror stack on the light-exit facet, wherein the mirror stack comprises two or more layers of dielectric material, wherein the mirror stack has a reflectivity into the active region that is greater in laser diode-component form than when the laser diode is integrated into an apparatus, and wherein the laser diode is configured to be integrated into the apparatus to direct light from the light-exit facet of the laser diode to a waveguide in the apparatus.
2 . The laser diode of claim 1 , wherein the two or more layers comprise an outermost layer of dielectric material, and wherein the mirror stack has a reflectivity into the active region that is greater when the outermost layer is adjacent to air, vacuum, and combinations thereof, than when the laser diode is integrated into an apparatus.
3 . The laser diode of claim 1 , wherein the two or more layers comprise an outermost layer of dielectric material that has a refractive index greater than at least one other layer of dielectric material in the mirror stack.
4 . The laser diode of claim 3 , wherein the two or more layers comprise a plurality of layers of dielectric material, wherein a refractive index of each layer is greater than a refractive index of each adjacent layer or less than the refractive index of each adjacent layer.
5 . The laser diode of claim 4 , wherein the plurality of layers comprises at least three layers.
6 . The laser diode according to claim 2 , wherein the refractive index of the outermost layer is greater than a refractive index of air and a refractive index of non-mirror stack material adjacent to the outermost layer when the laser diode is integrated into the apparatus.
7 . The laser diode of claim 6 , wherein the non-mirror stack material comprises a dielectric coupling medium.
8 . The laser diode of claim 7 , wherein the dielectric coupling medium is chosen from silicon dioxide, silicon nitride, aluminum oxide, and combinations thereof.
9 . The laser diode of claim 1 , wherein the mirror stack has a reflectivity into the active region in laser diode-component form of at least 5% at a wavelength from 800 nm to 860 nm, and wherein the mirror stack has a reflectivity into the active region of less than 1% at a wavelength from 800 nm to 860 nm when the laser diode is integrated into the apparatus.
10 . The laser diode of claim 1 , wherein each layer of the mirror stack has a thickness from 50 nm to 300 nm.
11 . The laser diode of claim 1 , wherein each layer of the mirror stack has a thickness from 50 nm to 190 nm.
12 . The laser diode of claim 1 , wherein each layer of the mirror stack comprises a dielectric material chosen from an oxide, a nitride, and combinations thereof.
13 . The laser diode of claim 1 , wherein each layer of the mirror stack comprises a dielectric material chosen from silicon dioxide, silicon oxynitride, silicon nitride, aluminum oxide, tantalum oxide, titanium oxide, tantalum oxide, niobium oxide, and combinations thereof.
14 . A substrate comprising a plurality of laser diodes of claim 1 .
15 . An apparatus comprising:
a substrate;
a laser diode of claim 1 , wherein the laser diode is located on the substrate;
a waveguide located on the substrate and optically coupled to receive light from the laser diode; and
a near-field transducer located on the substrate and optically coupled to receive light from the waveguide.
16 . The apparatus of claim 15 , further comprising one or more optical elements located on the substrate, wherein the one or more optical elements are external to the laser diode, and wherein the one or more optical elements are configured to reflect light received from the laser diode to the active region of the laser diode for lasing.
17 . The apparatus of claim 16 , wherein the one or more optical elements have a reflectivity into the active region of at least 3% at a wavelength from 800 nm to 860 nm.
18 . The apparatus of claim 16 , wherein the one or more optical elements are chosen from Bragg grating, diffraction grating, one or more mirrors, and combinations thereof.
19 . A data storage device comprising at least one apparatus of claim 15 .
20 . A computing system comprising a plurality of data storage devices of claim 19 .