Читать книгу VCSEL Industry - Babu Dayal Padullaparthi - Страница 4

1 Chapter 1Figure 1.1 Schematic of a vertical‐cavity surface‐emitting laser (VCSEL)....Figure 1.2 Schematic of semiconductor lasers (a) Edge‐emitting laser (EEL). ...Figure 1.3 Voltage–current (V–I) characteristic of a p‐n junction with no in...Figure 1.4 Double heterostructure laser. (a) The carrier densities of electr...Figure 1.5 Quantum well structure with separate optical confinement. (a) The...Figure 1.6 Population distribution of electrons and holes in semiconductor w...Figure 1.7 Optical gain of semiconductor vs. energy.Figure 1.8 Schematic of edge‐emitting Fabry‐Pérot lasers and VCSELs. The cou...Figure 1.9 Fabry‐Pérot cavity and resonant spectra. (a) Fabry‐Pérot cavity. ...Figure 1.10 The manufacturing processes of edge‐emitting lasers.Figure 1.11 The manufacturing and testing processes of VCSELs.Figure 1.12 A fully processed VCSEL layer structure on 6″ (150 mm) GaAs subs...Figure 1.13 Stages of VCSEL development. The inset figure shows the sketch o...Figure 1.14 The first demonstration of a surface‐emitting laser.Figure 1.15 Initial VCSELs achieving room‐temperature continuous operation. Figure 1.16 Origin of single‐mode and multi‐mode behavior in VCSELs.Figure 1.17 VCSEL‐based optical communication and sensing systems.Figure 1.18 Published papers on VCSEL.Figure 1.19 Application fields of VCSEL market as of 2021; data taken from v...Figure 1.20 The modified hype cycle of VCSEL industrialization.Figure 1.21 Total addressable market of VCSELs at module levels till 2025....

2 Chapter 2Figure 2.1 Cross section of an oxide‐confined VCSEL showing the basic compon...Figure 2.2 Energy band diagram of a 60 Å GaAs QW showing the quantum wells (...Figure 2.3 (a) Optical gain (cm⁻¹) for a 60 Å GaAs quantum well with N...Figure 2.4 Simplified schematic of a DBR mirror showing the reflections from...Figure 2.5 (a) Power reflectivity for 10, 20, 30, and 40 periods of a DBR mi...Figure 2.6 Light output as a function of current with the threshold current,...Figure 2.7 Forward voltage as a function of current with the series resistan...Figure 2.8 Plot of the electric field and index of refraction of a typical V...Figure 2.9 Optical emission spectra from a single‐mode VCSEL showing SMSR = ...Figure 2.10 (a) Optical emission spectrum of a multimode oxide isolated VCSE...Figure 2.11 Measured L‐I characteristic of a polarization‐controlled VCSEL w...Figure 2.12 Measured far‐field beam profile of a 25 Gbps VCSEL at I = 1, 3, ...Figure 2.13 Measured modulation transfer function (triangles), the intrinsic...Figure 2.14 Measured modulation transfer function of a typical VCSEL capable...Figure 2.15 Light output and forward voltage as a function of current at tem...Figure 2.16 Extracted performance metrics from Figure 2.15 as a function of ...Figure 2.17 Thermal response of a VCSEL active region (dashed lines) to elec...Figure 2.18 (a) Light output as a function of current for pulsewidths rangin...Figure 2.19 (a) Common top‐emitting VCSEL structure. (b) Bottom‐emitting VCS...

3 Chapter 3Figure 3.1 Core fields module‐level VCSELs market projection for the next fi...Figure 3.2 Chip demands of VCSELs for the next five years.Figure 3.3 Spine‐leaf DC architecture considerations in Cisco Systems.Figure 3.4 Typical (a) front‐ and (b) back‐facing smartphone layouts.Figure 3.5 Sources of VCSEL business attractiveness (“highway”).Figure 3.6 Fully processed 6″ (150 mm) GaAs VCSEL wafer.Figure 3.7 VCSEL demand and cost trends as a function of wafer size.Schematic 3.1 Multiple technological abilities of VCSELs.Figure 3.8 (a) PL map of GaN QWs grown on Si 8″ (200 mm) substrate. (Reprint...Figure 3.9 A schematic (a) cross section of generic, and (b) top‐views of so...Figure 3.10 (a) Etch depth sampling points and (b) its depth variation acros...Figure 3.11 Oxidation rate dependence of (a) time, (b) thickness, and (c) Al...Figure 3.12 Schematic of (a) oxidation depth as a function of Al(x) mole fra...Figure 3.13 Bathtub curve failure distribution trends of an optical componen...Schematic 3.1 Business models for III‐V opto foundries.Figure 3.14 VCSEL supply chain (with business models overlapped).Figure 3.15 Schematic of VCSEL product development or manufacturing stages f...Figure 3.16 Essential stages of cycle time during VCSEL product development....Figure 3.17 Examples of few MM and SM products.

4 Chapter 4Figure 4.1 Fixed and mobile Internet traffic in petabytes per month.Figure 4.2 Total Internet traffic (black line), Moore’s law at 1.5 years (bl...Figure 4.3 Total computing capacity (circles), the fastest (triangles), and ...Figure 4.4 (a) Fat tree or spine and leaf architecture preferred by data cen...Figure 4.5 Architecture of a modern Facebook data center [10].Figure 4.6 Typical cable carrier racks in a large data center. (a) This part...Figure 4.7 Evolution of communications standards speeds (a) Ethernet speeds ...Figure 4.8 Comparison of bandwidth density and energy per bit for some commo...Figure 4.9 Schematic of common optical interfaces used in networking equipme...Figure 4.10 Some common VCSEL‐based optical transceivers, active optical cab...Figure 4.11 (a, b) Converter for HDMI electrical to optical link extension c...Figure 4.12 Comparison of components for a VCSEL transmitter and an EEL‐base...Figure 4.13 Schematic of single, SDM, and WDM optical channels.Figure 4.14 Schematic of PAM‐2 and PAM‐4 signaling with representative optic...Figure 4.15 Schematic of a 5G network [17].Figure 4.16 Examples of some commercially available VCSELs capable of 25 Gbp...Figure 4.17 Differential gain as a function of In content in an 850 nm quant...Figure 4.18 (a) Modal gain and (b) differential gain as a function of carrie...Figure 4.19 (a) Photon lifetime as a function of etch depth into the DBR. (b...Figure 4.20 Schematic of the parasitic electrical components of a VCSEL.Figure 4.21 (a) Schematic of a photonic resonance oxide‐confined VCSEL. (b) ...Figure 4.22 (a) Schematic of a photonic resonance VCSEL defined by a photoni...Figure 4.23 Simulated S21 response and resulting eye diagrams for two differ...Figure 4.24 (a) Demonstration of equalization of the small signal response o...Figure 4.25 (a) Frequency response of a rectangular pulse (dashed line) and ...Figure 4.26 Summary of achieved data rates using PAM‐2 and PAM‐4 VCSELs [30]...Figure 4.27 Reference electrical drive signal (solid lines) and the resultin...Figure 4.28 Schematic of light transmission through graded in optical fiber ...Figure 4.29 Schematic of power launch profile in a MMF and the resulting enc...Figure 4.30 Chromatic dispersion bandwidth for OM4 MMF at 850 nm. The CD is ...Figure 4.31 (a) Junction are capacitance of a GaAs photodiode as a function ...Figure 4.32 Breakdown of power usage in a data center and the breakdown of p...Figure 4.33 Breakdown of power usage in a data center and the breakdown of p...

5 Chapter 5Figure 5.1 Three types of 3D sensing and imaging technologies object detecti...Figure 5.2 Various 3D sensing technologies, namely stereo vision, time‐of‐fl...Figure 5.3 Schematic of d‐TOF and i‐TOF.Figure 5.4 Principle of triangulation or structured light in 3D sensing/imag...Figure 5.5 Random patterns projected by commercial 3D sensors. (a) Microsoft...Figure 5.6 (a) A 3 W hexagonal VCSEL array chip for 3D sensing.(b) L‐I c...Figure 5.7 (a) Different contributions of losses in a VCSEL for reaching max...Figure 5.8 (a and b) Diffractive optical elements (DOE) diffusers and encode...Figure 5.9 VCSEL illumination module integrated with diffuser.Figure 5.10 (a) Schematic of radial transverse mode patterns overlapped with...Figure 5.11 A block diagram of 3D IR sensor module with its essential elemen...Figure 5.12 A four‐emitter VCSEL transmitter used as proximity sensor in iPh...Figure 5.13 A flip‐chip bonded 940 nm VCSEL array chip made for TOF flood il...Figure 5.14 (a) Concept of generation of distributed light or dot matrix....Figure 5.15 A 0.3 W VCSEL packaged chip from OSRAM for TOF and structured‐li...Figure 5.16 A vacuum sweeper robot from iRobot Braava m6 using structured‐li...Figure 5.17 Limited human vision perceptions and FOV.Figure 5.18 Schematic of reality‐virtuality continuum.Figure 5.19 Examples of AR‐based products: (a) smartphone and (b) smart glas...Figure 5.20 A 2.0 W VCSEL chip packaged with microlens arrays for facial rec...Figure 5.21 Market forecast for smartphones.

6 Chapter 6Figure 6.1 Classification of LiDARs for ranging applications.Figure 6.2 Concept of sensor fusion for advanced driver assistance systems (...Figure 6.3 Levels of ADAS with key functions.Figure 6.4 Automotive LiDAR detection in the city center, where both light s...Figure 6.5 Working principles of TOF, phase shift, and FMCW measurement tech...Figure 6.6 World first automotive standards qualified and individually addre...Figure 6.7 (a) Block diagram of LiDAR SOC.(b) A solid‐state LiDAR module...Figure 6.8 Display of scanned image from flash LiDAR system with VCSEL trans...Figure 6.9 A flash LiDAR module integrated on rear side of autonomous shuttl...Figure 6.10 Function of three kinds of LiDARs.Figure 6.11 Solar irradiance seen at the ground.Figure 6.12 MPE as energy density versus wavelength for various exposure tim...Figure 6.13 Structured light points from 2D‐VCSEL arrays with (a) high and (...Figure 6.14 TOF detection with AND gate and probability of capturing backgro...Figure 6.15 Majestic display of LiDAR transmitter made from 940 nm VCSEL arr...Figure 6.16 Individual (a) row‐, (b) column‐, and (c) zone‐wise addressable ...Figure 6.17 A car loaded with MEMS‐based LiDARs for MMS project.Figure 6.18 (a) Lumentum FWCM LOSA using 1550 nm DBR laser.(b) Far‐field...Figure 6.19 An example of highly reliable 940 nm VCSEL (a) bare and (b) pack...Figure 6.20 An infotainment system in the cockpit of an AV.Figure 6.21 Historical evolution of serial bus technologies.

7 Chapter 7Figure 7.1 Output beam characteristics of VCSEL, LED, and EELs.Figure 7.2 Coherence length of an illuminator as a function of the spectral ...Figure 7.3 Relative optical emission spectrum of LEDs, EELs, and VCSELs at −...Figure 7.4 Components of a VCSEL‐based optical mouse [12].Figure 7.5 VCSEL‐based infrared flashlight available on www.alibaba.comFigure 7.6 Infrared night vision camera with a VCSEL illuminator available o...Figure 7.7 Illuminator with 30 W of peak power and capable of direction illu...Figure 7.8 Thermal transit time as a function of distance between the emitte...Figure 7.9 Illuminator modules produced by Princeton Optronics (now AMS) cap...Figure 7.10 Night vision images collected with VCSEL illuminators [6]. Note ...Figure 7.11 Scaling of VCSEL power from a single emitter at 10 mW to systems...Figure 7.12 (a) A 10 kW heating system with over 3M VCSEL emitters, and (b) ...Figure 7.13 Map of heating applications and the required BPP and total optic...Figure 7.14 Map of heating applications and the required pulsewidth and powe...Figure 7.15 (a) Difference between flash lamp or carbon filament heaters and...Figure 7.16 Map of heating applications and the required pulsewidth and powe...

8 Chapter 8Figure 8.1 Schematic of InP‐, GaSb‐, and GaAs‐based VCSEL technologies used ...Figure 8.2 (a) Analogy of a VCSEL to an optical fiber showing multiple trans...Figure 8.3 A single‐mode VCSEL with a small metal aperture used in laser pri...Figure 8.4 (a) Cross section of a VCSEL with surface relief etch. (b) SEM im...Figure 8.5 (a) Cross‐section schematic of a photonic crystal VCSEL. (b) Top‐...Figure 8.6 (a) Orientation of [100] GaAs substrate and (b) [n11] GaAs substr...Figure 8.7 (a) A VCSEL structure grown on a [311]B substrate and (b) the opt...Figure 8.8 (a) Top‐view image of a VCSEL with a surface grating. (b) AFM ima...Figure 8.9 Polarization‐controlled VCSEL using an HCG.Figure 8.10 (a) Simplified schematic of a VCSEL with a widely tunable wavele...Figure 8.11 (a) Simplified schematic of a tunable VCSEL with a cantilever DB...Figure 8.12 Evolution of the tuning ratio as a function of time [22].Figure 8.13 (a) Schematic of an LED‐ and‐VCSEL based mouse [26]. (b) 3D sche...Figure 8.14 (a) Schematic of self‐mixing [28]. (b) Philips Twin‐Eye™ sensor ...Figure 8.15 Optical Encoder. (a) Schematic of an optical encoder. (b) Chip s...Figure 8.16 Schematic of a VCSEL‐based laser printing engine.Figure 8.17 (a) 40 element VCSEL array used in an industrial laser printer, ...Figure 8.18 Absorption spectrum and detectivity level of some important gase...Figure 8.19 VCSEL wavelengths available for gas sensing form Vertilas (www.v...Figure 8.20 GaSb VCSEL designed to operate in the mid‐infrared region.Figure 8.21 (a) Portion of the atomic spectrum of Cs showing the relevant VC...Figure 8.22 (a) Schematic of a physics package for a VCSEL‐based atomic cloc...Figure 8.23 The oscillator module for an atomic clock.Figure 8.24 The principle of SS‐OCT.Figure 8.25 Images of OCT: (a) Vasculature and capillaries (red and yellow) ...Figure 8.26 Cross‐sectional image of the eyeball by OCT using VCSEL: (a) OCT...

9 Chapter 9Figure 9.1 VCSEL structures for LW‐VCSEL.Figure 9.2 (a) LW‐VCSEL die. (b) LW‐VCSEL in an LC fiber TOSA. (c) Tunable V...Figure 9.3 Light field and single‐photon emission [30].Figure 9.4 Concept of quantum encryption (K. Iga).

10 Chapter 10Figure 10.1 Estimated future VCSEL chip markets.Figure 10.2 Schematic of past, present, and future VCSEL markets and applica...

11 Appendix AFigure A.1 Key stages of VCSEL development for mass production.Figure A.2 (a) A generic top‐emitting, oxide‐confined VCSEL structure for ma...Figure A.3 (a) Basic elements in MQW‐based active region. (b) Example of pho...Figure A.4 Structure of (a) oxide window (OW) and tilted OW at (b) node and ...Figure A.5 The concepts of thermal conductivity of Al_xGa_1−xAs systems ...Figure A.6 Discretization of device into (a) finite difference (FDM/FDTD) an...Figure A.7 Flowchart of VCSEL device in numerical modeling.Figure A.8 Interplay of material properties with strength of simulations for...Figure A.9 Schematics of active regions with (a) 1.0λ and (b) 0.5λFigure A.10 (a) A schematic of surface relief integrated VCSEL.(b) A sch...Figure A.11 Schematics of (b) electrical equivalent, (a) dual and shallow ox...Figure A.12 (a) Concept of n_eff. (b) Phase conditions and experimental varia...Figure A.13 (a) LIV characteristics of VCSELs with different top heat sink s...Figure A.14 Design (dotted line) and operation (continuous line) PCE charact...

12 Appendix BFigure B.1 Technologies and materials used for VCSEL growth at various wavel...Figure B.2 Materials lattice constant vs bandgap at various wavelengths. App...Figure B.3 GaAs epi‐wafer share in photonics.Figure B.4 Schematics of epitaxial growth in (a) MBE and (b) MOCVD.Figure B.5 Key growth parameters as black‐box items.Figure B.6 (a) Multiple sections and growth temperature relationship in a VC...Figure B.7 Flowchart of MOCVD calibrations for a VCSEL structure.Figure B.8 Quasi layer structures for (a) Al(x) composition and (b) p‐ and n...Figure B.9 Quasi layer structures for (a) p‐DBR and (b) n‐DBR reflectivities...Figure B.10 (a) PL wavelength map of 6″ (150 mm) wafer for 940 nm VCSSEL....Figure B.11 (a) Mini and (b) full VCSEL structures to grow in a MOCVD system...Figure B.12 SIMS doping profile of p‐DBR, AR and n‐DBR in a VCSEL structure....Figure B.13 PL map of GaN QWs grown on Si 8″ (200 mm) substrate.

13 Appendix CFigure C.1 (a) Cross‐sectional image of HEMT.(b) Cross‐sectional image o...Figure C.2 (a) Top anode–bottom cathode (TB), and (b) top anode–top cathode ...Figure C.3 (a) DOE and lot steps and (b) process and product oriented steps ...Figure C.4 Schematic of visual inspection patterns/contours for (a) datacom ...Figure C.5 Schematic generic process flow of high‐speed (datacom) top‐emitti...Figure C.6 Sequence of process flow for (a) top anode–bottom cathode (TB), a...Figure C.7 Schematic generic process flow of high‐power (3D sensing and imag...Figure C.8 Key process conditions for VCSEL manufacturing.Figure C.9 Example of Six Sigma methodology used in parameter analysis.Figure C.10 Wafer probe (a) power and (b) wavelength maps for a fully proces...

14 Appendix DFigure D.1 Schematic of a VCSEL manufacturing process showing test aggregati...Figure D.2 Schematic of VCSEL testing stages.Figure D.3 (a) Measured VCSEL reflectance spectrum on wafer immediately afte...Figure D.4 VCSEL oxide aperture imaged with different center wavelengths sho...Figure D.5 VCSEL oxide aperture measurement interpolated onto a 150 mm diame...Figure D.6 (a) Variation of VCSEL threshold current and (b) slope efficiency...Figure D.7 Wafer maps showing the variation in DC‐measured parameters on a 1...Figure D.8 Box plots showing the variation in DC measured parameters on a 15...Figure D.9 Correlation of threshold current and wall plug efficiency as a fu...Figure D.10 Wafer map of relaxation oscillation frequency sampled and mapped...Figure D.11 Power emission form a single die on a wafer under different puls...

15 Appendix EFigure E.1 Reliability bathtub curve showing the early failure rate (red), r...Figure E.2 (a) Plot of acceleration factor as a function of temperature for ...Figure E.3 (a) Plot of wavelength as a function of P_DISS and (b) the calcula...Figure E.4 Thermal image of a two‐dimensional VCSEL array and the measured t...Figure E.5 (a) top view from a TEM cross‐section of a VCSEL active region th...Figure E.6 (a) Plan‐view TEM image of an oxide isolated VCSEL showing the pr...Figure E.7 Cross‐section view of a typical oxide isolated VCSEL with a lumpe...Figure E.8 Reverse I‐V characteristic of a normal VCSEL and one that has bee...Figure E.9 Forward bias electroluminescence image showing ESD damage locatio...Figure E.10 Plan‐view and cross‐sectional views of EOS, HBM, MM, and ESD dam...Figure E.11 Damage threshold for HBM ESD events as a function of the emissio...Figure E.12 (a) shows low‐current luminescence image of a VCSEL with a darke...Figure E.13 Measured power output as a function of current for a VCSEL prior...Figure E.14 Damage threshold for HBM ESD events as a function of the emissio...Figure E.15 Results from an automotive AECQ‐102 qualification [27].

16 Appendix FFigure F.1 Measurement configuration for eye‐safety classification.Figure F.2 Plot of the MPE limit in J/cm² as a function of exposure time (le...Figure F.3 Schematic of the optical system used to determine extended source...

17 Appendix GFigure G.1 Features and format of laser display [6].Figure G.2 Principles of laser projectors: (a) mems scanner and (b) spatial ...Figure G.3 Gamut standards [9].Figure G.4 Gamut examples. (The color of each system depends on devices used...Figure G.5 Image of semiconductor laser set for primary color display.Figure G.6 Method of extracting green color from nonlinear crystals placed i...Figure G.7 Second harmonic generation VCSEL generating green in the resonato...Figure G.8 Laser‐backlight liquid‐crystal display [5, 6, 16].

18 Appendix HFigure H.1 Attenuation of typical POF as a function of wavelength.Figure H.2 Normalized absorption spectra of several blood hemoglobins as a f...Figure H.3 Implementation of a blood oximeter in the Apple Watch using four ...

19 Appendix IFigure I.1 Bandgap energy vs. lattice constants.Figure I.2 InGaN‐VCSEL reports.Figure I.3 Lasing light from blue VCSEL.Figure I.4 VCSEL cross‐section with curved dielectric mirrors [29].Figure I.5 Full (white) color generation from red/green/blue VCSELs.

20 Appendix JSchematic J.1.1 Classification of photodetectors for light‐based communicati...Figure J.1.2.1 Schematic of reverse‐biased p‐n junction (light characteristi...Figure J.1.2.2 (a) Absorption coefficient as a function of wavelength for di...Figure J.2.1 Schematic of sources of noise in photodetectorsFigure J.3.1.1 Schematic x‐section of (a) p‐n and (b) p‐i‐n PDs with associa...Figure J.3.2.1 (a) Schematic structure of APD with impact ionization and (b)...Figure J.3.3.1 Operating regimes with non‐linear avalanche processes in SPAD...Figure J.3.4.1 (a) Cross section of single SAPD as microcell SiPM, and (b) i...Figure J.3.6.1 Structure and charge transfer in (a–e) CCD and (f–g) 4T CMOS ...Figure J.3.7.1 (a) FLIM images HeLa cells (20–40 μm diameter) with visible i...