# US 10,320,153 B1 · Systems and methods of an L-switched light emission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,153 B1 - Document ID: US10320153B1 - Status: Granted - Kind: B1 - Application number: 14/714,248 - Filed: 2015-05-15 - Granted: 2019-06-11 - Earliest claimed: 2014-07-15 - Applicants: Rudolf Heinrich Binder; Nai-Hang Kwong; Paul Bryan Lundquist - Inventors: Rudolf Heinrich Binder; Nai-Hang Kwong; Paul Bryan Lundquist - Web page: https://patentgrep.com/patent/US10320153B1 ## CPC - H01S 5/34333: {with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser} - H01S 5/04253: {having specific optical properties, e.g. transparent electrodes} - H01S 5/04256: {characterised by the configuration} - H01S 5/0614: {controlled by electric field, i.e. whereby an additional electric field is used to tune the bandgap, e.g. using the Stark-effect} - H01S 5/3214: {comprising materials from other groups of the Periodic Table than the materials of the active layer, e.g. ZnSe claddings and GaAs active layer} - H01S 5/3415: {containing details related to carrier capture times into wells or barriers} - H01S 5/02469: {Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC} - H01S 5/02484: {Sapphire or diamond heat spreaders} - H01S 5/026: Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers (stabilisation of output H01S5/06) - H01S 5/041: {Optical pumping} - H01S 5/0424: {lateral current injection} - H01S 5/305: {characterised by the doping materials used in the laser structure} - H01S 5/3054: {p-doping} - H01S 5/3416: {tunneling through barriers} - H01S 5/4043: {with vertically stacked active layers} - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract Provided herein are systems and methods for switching the generation of light emissions using charge separation in a gain medium to manipulate carrier lifetimes. For a given output pulse energy, extended carrier lifetimes may allow carrier generation powers to be reduced and/or carrier generation times to be extended. L-switching of light output from a gain medium may be combined with other switching schemes utilizing different approaches to control lasing, such as Q-switching. ## Claims ### Claim 1 A light emitter comprising: a gain structure for providing an optical gain via stimulated emission, the gain structure including a confinement region for charge carriers within a direct-bandgap structure defined by a continuum of charge carrier densities of states along each of a first dimension and a second dimension, the first dimension and the second dimension comprising a planar region of the confinement region, the continuum of charge carrier densities of states adapted for accumulating charge carriers in the direct-bandgap structure, wherein the direct-bandgap structure is configured for producing a stimulated pulsed-light emission comprising a multitude of photons; an input surface of the light emitter configured to route light to the confinement region where the light undergoes the optical gain via stimulated emission; an optical emission path of the light emitter that is orthogonal the planar region of the confinement region and that directs light created via stimulated emission in the gain structure through an emission surface of the light emitter; and a plurality of electrodes configured to modify an electric field in a direction orthogonal to the planar region of the confinement region to spatially-redistribute charge carriers within the direct-bandgap structure into at least: A) a spatially-accumulating configuration of the charge carriers that does not result in the stimulated pulsed-light emission from the confinement region, and that: 1. accumulates charge carriers into the continuum of charge carrier densities of states in the direct-bandgap structure, while the direct-bandgap structure is in a direct-bandgap state, in the confinement region; and 2. distributes the accumulated charge carriers, of both polarities, into portions of the direct-bandgap structure in the confinement region; and B) a spatially-overlapping configuration of the accumulated charge carriers for depletion of the accumulated charge carriers that have been accumulated in the spatially-accumulating configuration in the continuum of charge carrier densities of states in the direct-bandgap structure in the confinement region, wherein the spatially-overlapping configuration spatially-distributes the accumulated charge carriers to produce the stimulated pulsed-light emission comprising the multitude of photons from the confinement region. ### Claim 2 (depends on 1) The light emitter of claim 1, wherein the electric field is due in part to a built-in voltage gradient within the gain structure at a zero bias voltage along the confinement dimension. ### Claim 3 (depends on 1) The light emitter of claim 1, wherein the electric field is due in part to a non-zero bias voltage on the electrodes. ### Claim 4 (depends on 1) The light emitter of claim 1, further comprising: a pumping source configured to accumulate the charge carriers over a period of time into the spatially-accumulating configuration in the confinement region. ### Claim 5 (depends on 4) The light emitter of claim 4, wherein the pumping source is an optical pumping source of pump light, configured to populate the charge carriers into the spatially-accumulating configuration in the direct bandgap structure by absorption of the pump light by the light emitter. ### Claim 6 (depends on 5) The light emitter of claim 5, wherein the optical pumping source is a pump diode. ### Claim 7 (depends on 1) The light emitter of claim 1, further comprising: a carrier injection source for populating the charge carriers in the spatially-accumulating configuration in the confinement region. ### Claim 8 (depends on 7) The light emitter of claim 7, wherein the carrier injection source is a heterojunction. ### Claim 9 (depends on 1) The light emitter of claim 1, wherein the light emitter is part of a laser system including an optical laser cavity. ### Claim 10 (depends on 1) The light emitter of claim 1, wherein the optical emission path traverses at least one of the plurality of electrodes for producing the electric field orthogonal to the planar region of the confinement region and, wherein the at least one of the plurality of electrodes is at least partially transmissive. ### Claim 11 (depends on 10) The light emitter of claim 10, wherein the optical emission path traverses at least two electrodes of the plurality of electrodes that are each at least partially transmissive. ### Claim 12 (depends on 10) The light emitter of claim 10, wherein the light emitter is configured with a reflective surface to create a reflected light path including the optical emission path through the at least one of the plurality of electrodes. ### Claim 13 (depends on 1) The light emitter of claim 1, wherein the emission surface of the light emitter and the input surface of the light emitter comprise a single surface of the light emitter. ### Claim 14 (depends on 1) The light emitter of claim 1, wherein the emission surface of the light emitter is a different surface of the light emitter than the input surface of the light emitter.