Compact ultra-violet laser diode configured for lidar system for air turbulence detection
According to the present invention, techniques related generally to correction of atmospheric turbulence beam control (CAT) configured with a distributed feedback (DFB) laser diode device are provided. In particular, the present invention provides a method and system for using a DFB laser diode device for correcting atmospheric turbulence beam control. Merely by way of example, the invention can be applied to a variety of applications, including satellites, weather, airplanes, spaceships, naval vessels, or among other navigational tools.
1 . A light detection and ranging system comprising:
an aluminum gallium nitride (AlGaN) containing laser diode device configured to emit electromagnetic radiation having a wavelength ranging from 280 nm to 470 nm, and comprising:
a gallium and nitride containing substate member;
an n-type gallium nitride containing cladding material overlying the substrate member;
a first n-type gallium nitride containing waveguide material overlying the n-type gallium nitride containing cladding material;
a first barrier material overlying the first n-type gallium nitride material, the first barrier material comprising an aluminum, gallium, and nitrogen containing material;
a plurality of quantum well regions overlying the first barrier material, the plurality of quantum well regions comprising at least a first quantum well region and a second quantum well region, each of the quantum well regions ranging in thickness from 2 nanometers to 5 nanometers, each quantum well region comprising an aluminum, gallium, and nitrogen containing material;
a second barrier material comprising aluminum, gallium, and nitrogen containing material configured between the first quantum well region and the second quantum well region;
a confinement factor characterizing each of the quantum well regions is greater than one percent per quantum well region;
an electron blocking material overlying the quantum well regions;
a p-type gallium nitride containing waveguide material overlying the electron blocking material;
a p-type gallium and nitride containing cladding material overlying the p-type gallium nitride containing waveguide material;
a contact region comprising an indium tin oxide material overlying the p-type gallium and nitrogen cladding material;
a front facet coupled to a front side of the n-type gallium nitride containing waveguide material and a front side of the p-type gallium nitride containing waveguide material, the front facet comprising an antireflective coating;
a back facet coupled to a back side of the n-type gallium nitride containing waveguide and a back side the p-type gallium nitride containing waveguide, the back facet comprising an optical coating;
an optical cavity configured between the front facet and the back facet including the plurality of quantum well regions defined between the front facet and the back facet;
a monolithically integrated diffraction grating configured within or overlying the contact region and configured to reflect electromatic radiation emitted from one or more of the plurality of quantum well regions and cause the electromagnetic radiation to amplify the electromagnetic radiation using stimulated emission in the optical cavity thereby outputting a laser light beam from the front facet;
a characteristic dimension of m(λ/2n) characterizing a pitch of two or more lines configured in the monolithically integrated diffraction grating, where m is an order of a grating and n is a refractive index of a semiconductor material for the optical cavity;
a sensing device operably coupled to the AlGaN containing laser diode device and configured to receive a signal scattered from an interaction of an air turbulence and an emission 47 of the electromagnetic radiation from the AlGaN containing laser diode and detect the air turbulence from the scattered signal; and
a controller operably coupled to the sensing device and the AlGaN containing laser diode device, the controller being adapted to process a signal generated from the sensing device.
2 . The system of claim 1 wherein the monolithically integrated diffraction grating comprises a single grating region or a plurality of grating regions; wherein the p-type gallium nitride containing waveguide material comprising aluminum; and wherein the n type gallium nitride containing waveguide material comprises aluminum.
3 . The system of claim 1 wherein the back facet comprises an antireflective coating or a reflective coating for the optical coating.
4 . The system of claim 3 where in the antireflective coating on the front facet and the back facet characterizes a phase shifted distributed feedback laser device.
5 . The system of claim 3 wherein the antireflective coating on the back facet and the reflective coating on the front facet characterize a non-phase shifted distributed feedback laser device.
6 . The system of claim 1 wherein the system is mounted on an aircraft capable of flight, the AlGaN containing lase device being coupled to a front region of a fuselage or wing region and the sensing device being coupled to a wing region of the aircraft.
7 . The system of claim 1 wherein the AlGaN containing laser device is monolithically integrated to form a compact structure.
8 . The system of claim 1 wherein the AlGaN containing laser device is a distributed feedback laser device or a tunable laser diode device configured for emitting a blue color light.
9 . The system of claim 1 further comprising an input handler configured to the sensing device, the input handler being coupled to process the signal in an inference engine comprising a plurality of nodes, the number of nodes ranging from 10,000 to over 1 million to output a signal detecting clear air turbulence or another anomaly.
10 . The system of claim 1 wherein the electromagnetic radiation has a wavelength range selected from 450-470 nm, 400-460 nm, 320-400 nm, or 250-320 nm.
11 . The system in claim 1 wherein the AlGaN containing laser diode device is pulsed by direct current configured to a modulation.
12 . The system in claim 1 wherein the AlGaN containing laser diode device is modulated by an integrated modulator.
13 . The system in claim 1 wherein the AlGaN containing laser diode device is steered and reflected into the sensor device using a free space optical system, shaped lens, a MEMS system, or steerable mirror.
14 . The system of claim 1 further comprising a driver device coupled to the AlGaN containing laser diode device.
15 . The system of claim 1 wherein the AlGaN containing laser diode device further comprises a power of one milliwatt and greater characterizing the AlGaN containing laser diode device.
16 . A light detection and ranging system comprising:
an AlGaN containing laser diode device configured to emit electromagnetic radiation having a wavelength ranging from 280 nm to 470 nm, and comprising:
a gallium and nitride containing substate member;
an n-type gallium nitride containing cladding material overlying the gallium and nitride containing substrate member;
an n-type aluminum gallium nitride containing waveguide material overlying the n-type gallium nitride containing cladding material;
a first barrier material overlying the n-type aluminum gallium nitride 9 waveguide material, the first barrier material comprising an aluminum, gallium, and nitrogen containing material;
a plurality of quantum well regions overlying the first barrier material, the plurality of quantum well regions comprising at least a first quantum well region and a second quantum well region, each of the quantum well regions ranging in thickness from 2 nanometers to 5 nanometers, each of the quantum well regions comprising an aluminum, gallium, and nitrogen containing material;
a second barrier material comprising aluminum, gallium, scandium, and nitrogen containing material configured between the first quantum well region and the second quantum well region;
a confinement factor characterizing each of the plurality of quantum well regions is greater than one percent per quantum well region;
an electron blocking material overlying the plurality of quantum well regions;
a p-type aluminum gallium nitride containing waveguide material overlying the electron blocking material;
a p-type gallium nitride containing cladding material overlying the p-type aluminum gallium nitride containing waveguide material;
a contact region comprising an indium tin oxide material overlying the p-type gallium nitride cladding material;
a front facet coupled to the n-type aluminum gallium nitride containing waveguide material and the p-type aluminum gallium nitride containing waveguide material, the front facet comprising an antireflective coating;
a back facet coupled to the n-type aluminum gallium nitride containing waveguide material and the p-type aluminum gallium nitride containing waveguide material, the back facet comprising an optical coating;
an optical cavity configured between the front facet and the back facet and comprising the plurality of quantum well regions defined between the front facet and the back facet such that the front facet is opposite of the back facet;
a monolithically integrated diffraction grating configured within or overlying the contact region and configured to reflect electromatic radiation emitted from one or more of the plurality of quantum well regions and cause the electromagnetic radiation to amplify the 40 electromagnetic radiation using stimulated emission thereby outputting a laser light beam from the front facet;
a characteristic dimension of m(λ/2n) characterizing a pitch between at least a pair of lines of the monolithically integrated diffraction grating, where m is the order of a grating; and n is a refractive index of a semiconductor material for the optical cavity;
a sensing device operably coupled to the AlGaN containing laser diode device and configured to receive a signal scattered from an interaction of an air turbulence and an emission of the electromagnetic radiation and detect the air turbulence from the scattered signal; and
a controller operably coupled to the sensing device and the AlGaN containing laser diode device, the controller being adapted to process a signal generated from the sensing device.
17 . The system of claim 16 wherein the monolithically integrated diffraction grating comprises a single grating region or a plurality of grating regions.
18 . The system of claim 16 wherein the front facet comprises an antireflective coating or a reflective coating for the optical coating; wherein the antireflective coating on the front facet and the back facet characterizes a phase shifted distributed feedback laser device; or wherein the antireflective coating on the back facet and the reflective coating on the front facet characterizes a non-phase shifted distributed feedback laser device.
19 . The system of claim 16 wherein the system is mounted on an aircraft, the AlGaN containing lase device being coupled to a front region of a fuselage and the sensing device being coupled to a wing region of the aircraft.
20 . The system of claim 16 wherein the AlGaN containing laser device is monolithically integrated; wherein the AlGaN containing laser device is a distributed feedback laser device or a tunable laser diode device configured for emitting a blue color light.
21 . The system of claim 16 further comprising a input handler configured to the sensing device, the input handler being coupled to process the signal in an inference engine comprising a plurality of nodes, the number of nodes ranging from 10,000 to over 1 million to output a signal detecting clear air turbulence or another anomaly.
22 . The system of claim 16 wherein the electromagnetic radiation has a wavelength range selected from 450-470 nm, 400-460 nm, 320-400 nm, or 250-320 nm.
23 . The system in claim 16 wherein the AlGaN containing laser diode device is pulsed by direct current modulation or wherein the AlGaN containing laser diode device is modulated by an integrated modulator.
24 . The system in claim 16 wherein the laser diode device is steered and reflected into the sensor device using a free space optical system, shaped lens, a MEMS system, or steerable mirror.
25 . The system of claim 16 further comprising a driver device coupled to the AlGaN containing laser diode device.
26 . The system of claim 16 wherein the AlGaN containing laser diode device further comprising a power of one milliwatt and greater characterizing the AlGaN containing laser diode device.