National Academies Press: OpenBook

Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing (2014)

Chapter: Appendix C: Laser Sources and Their Fundamental and Engineering Limits

« Previous: Appendix B: Meetings and Participating Orginizations
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

C

Laser Sources and Their Fundamental and Engineering Limits

This appendix summarizes in table form the characteristics of lasers and other light sources systems important to active EO sensing and their fundamental and practical engineering limitations. Tables C-1 to C-4 are called out in the laser discussion in Chapter 4. Tables C-5 through C-12 are summarized in Chapter 5.

TABLE C-1 Key Characteristics of Edge-Emitting Interband Diode Lasers

Material Wavelength Range (nm) Single-emitter Power Single-Emitter Efficiency (%) Bar Power (W) Bar Efficiency (%)
GaInN ~380 0.2 10-15
400, 450 1.2-1.6 25-30
~520 0.05 <<10
AlGaInP 639-690 0.75-1.5 20-25
632, 635, 638 2.5-8 W >25
675 20 W >35
GaAlAs 793, 808, 852 5-7 W 60 60-200 50-60
InGaAs 915-976 10-15 60-70 120-200 60-70
1,064 5 W 50-55 60 50-55
InGaAsP/ 1,470-1,532 5-7 W 30-45 60-100 30-40
AlInGaAs 1,600-1,700 3 W 20-25 40 20-25
AlGaInAsSb 1,900-2,100 1-2 W 10-15 15-20 W 10-20
2,300-2,500 1 W 5-10

SOURCE: Data provided by Steven Patterson, DILAS, Tucson, Ariz.

Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-2 Key Characteristics of State of-the-Art Cascade Diode Lasers

QCL: InP/InGaAs/InAlAs

Wavelength of best operation: 4-5 µm; output power: 5 W, CW with 21% efficiency (obtained with AlAs inserts to increase the effective barrier heights).

Wavelengths between 2.9 and 4 µm and from 5 to 150 µm operate with lower performance.

 
QCL: GaAs/GaAs/AlGaAs

Wavelength of best operation: 10 µm; output power: 80 mW at 77 K; CW up to 150 K.

Far-IR wavelength: 100 µm; output: 8 mW, CW at 45 K with 0.2 % efficiency.

No CW above 117 K.

Full wavelength range = 9-300 µm; non-competitive in mid-IR.

 
QCL: GaSb/(InAs/AlSb)

Wavelengths; 2.6 – 5 µm. CW only with TE cooler

 
QCL: InP/InGaAs/AlAsSb

To date, non-competitive with InGaAs/InAlAs at any wavelength.

No CW room temperature operation.

 
ICL on GaSb

Wavelength: 3-4.2 µm; output power: 360 mW; efficiency: 15%.

Wavelengths from 4.2-6 mm with lower performance.

 
ICL on InAs

Wavelength: 5.3 µm; Output Power: 40 mW at 180 K; CW up to 248 K.

Wavelength range: 5.3-10.4 mm.

NOTE: QCL, quantum cascade laser; ICL, interband cascade laser.

SOURCE: Data provided by Jerry Meyer and Igor Vurgaftman, Naval Research Laboratory, Washington, D.C.

TABLE C-3 Characteristics of Several Common Bulk Laser Materials

Material Wavelength (nm) Storage Time (msec) Cross section (cm2) Gain Linewidth (nm) Saturation Fluence (J/cm2)
Nd:YAG 1,064 0.24 2.8 × 10-19 0.6 0.66
Nd:vanadate 1,064 0.09 1.1 × 10-18 1.0 0.17
Nd:YLF 1,047 0.485 1.8 × 10-19 1.0 1.0
Nd:glass 1,050-1,060 0.3-0.4 3-4 × 10-20 20-30 4.7-6.3
Yb:YAG 1,030 0.95 2.1 × 10-20 9 9.2
Yb:YAG(77K) 1,030 0.85 1.1 × 10-19 1.5 1.8
Er:YAG 1,645 7.6 5.0 × 10-21 5 24
Er:glass 1,550 7.9 8.0 × 10-21 55 16
Ho:YAG 2,090 8.5 1.3 × 10-20 25 7.3
Ho:YLF 2,050 15 1.8 × 10-20 25 5.3
Ti:sapphire 800 0.0032 3.0 × 10-19 225 (100 THz) 0.83
Cr:ZnSe 2,450 0.006 1.3 × 10-18 1,000 (50 THz) 0.06
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-4 Properties of Hybrid Lasers

Material Wavelength (nm) Pulse Energy (mJ) Pulsewidth (ns) Pulse Rate (Hz)
Er:YAGa 1,617 30 42 30
Er:YAGb 1,645 4.2 100 1,000
Er:YAGc 1,645 1.6 1.1 10,000
Er:YAGd 1,645 60 W CW
Ho:YLFe 2,050 170 20 100
Ho:YLFf 2,050 100 20 1,000
Ho:YLFg 2,050 115 W CW
Ho:YAGh 2,090 125 20 100
Ho:YAGi 2,090 22 70 1,000
Ho:YAGj 2,090 1.7 50 35,000

a J.W. Kim, J.I. Mackenzie, J.K. Sahu, and W.A. Clarkson, “Hybrid fibre-bulk erbium lasers—Recent progress and future prospects,” 7th EMRS DTC Technical Conference, Edinburgh, 2010.

b D.Y. Shen, J.K. Sahu, and W.A. Clarkson, “Highly efficient in-band pumped Er:YAG laser with 60 W of output at 1645 nm,” Opt. Lett. 31:754, 2006.

c R.C. Stoneman, R. Hartman, E.A. Schneider, A.I.R. Malm, S.R. Vetorino, C.G. Garvin, J.V. Pelk, S.M. Hannon, and S.W. Henderson, “Eye-safe 1.6-µm Er:YAG transmitters for coherent laser radar,” Proceedings 14th Coherent Laser Radar Conference, July 8-13, 2007, Snowmass, Colo.

d D.Y. Shen, J.K. Sahu, and W.A. Clarkson, “Highly efficient in-band pumped Er:YAG laser with 60 W of output at 1645 nm,” Opt. Lett. 31:754, 2006.

e A. Dergachev, “45-dB, Compact, Single-Frequency, 2-µm Amplifier,” paper FTh4A.2 in Lasers, Sources, and Related Photonic Devices, OSA Technical Digest (CD), Optical Society of America, 2012.

f Ibid.

g Ibid.

h K. Schmidt, C. Reiter, H. Voss, F. Maßmann, and M. Ostermeyer, “High Energy 125mJ Ho: YAG (2.09 um) MOPA Double Pass Laser System Pumped by CW Thulium Fiber Laser (1.9 um),” paper CA3_4 in CLEO/Europe and EQEC 2011 Conference Digest, OSA Technical Digest (CD), OSA, 2011.

i Ibid.

j A. Hemming, J. Richards, A. Davidson, N. Carmody, S. Bennetts, N. Simakov, and J. Haub, “99 W mid-IR operation of a ZGP OPO at 25 percent duty cycle,” Opt. Express 21:10062, 2013.

Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-5 Fundamental Limits of Diode Lasers: Interband, Edge-Emitting

Property Value Limit Reason Comments
Electrical efficiency (theory) 100% Fundamental energy conservation One photon per one injected carrier
Electrical efficiency (actual) 40-70% Multiple device issues Ohmic losses, injected carrier spreading away from lasing region, active region absorption loss, Auger losses (at long wavelengths)
Wavelength >380 nm Materials Limit of GaAlN material, no other large-bandgap II-VI has allowed PN junction fabrication
<520 nm Materials Limits of GaAlN material
>630 nm Materials Lack of semiconductors with bandgaps in green-yellow-red region that can form PN junctions
<2,500 nm Materials Limits on active materials and DBR structures
Power out (1 emitting facet, 1 TM) 0.1-0.5 W pn junction physics, facet damage Height of emitting region limited to 0.5 µm by junction height, width limited by multi-mode operation, intensity limited by facet damage levels
Power out (1 emitting facet, MultiTM) 15 W (at 9xx µm, less at others) pn junction physics, transverse lasing, facet damage Same height limit as above, width of emitting region limited by lasing in transverse direction, intensity limited by facet damage
Power out (1-cm-long, linear bar, multiple emitters) 200 W (at 9xx µm, less at others) Device temperature, limited by heat removal Efforts to improve heat removal are underway, to allow limit to become facet damage, but cost and reliability are challenges. Efficiency improvements will allow bars to generate higher powers
Spectral linewidth (single TM) Several MHz Coupling of diode current fluctuations to cavity refractive index Can be reduced to the kHz range through use of an external cavity

NOTE: TM = transverse mode.

Refer to Table C-1 for device properties as a function of wavelength.

Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-6 Diode Lasers Vertical Cavity (VCSEL)

Property Value Limit Reason Comments
Electrical efficiency (theory) 100% Fundamental energy conservation One photon per one injected carrier
Electrical efficiency (actual) 40-60% (8xx-9xx nm) Multiple device issues Ohmic losses, injected carrier spreading away from lasing region, absorption loss in active region, Auger losses (at long wavelengths)
Wavelength >410 nm Materials Limit of GaAlN material, no other large-bandgap II-VI has allowed PN junction fabrication
<503 nm Materials Limits of GaAlN material
>630 nm Materials Lack of semiconductors with bandgaps in green-yellow-red region that can form PN junctions
<2,000 nm Thermal activation The smaller bandgaps can be bridged with thermally activated carriers
Power out (1 emitting facet, 1 TM) 5-15 mW Active region heating Diameter of 1 TM limited to ~4 µm on chip by optical cavity, limits power for a given current
Power out (1 emitting facet, MTM) 5 W Active region heating region Done with 300-µm emitting region diameter
Power out (VCSEL arrays) 230 W (maximum at 9xx nm) Temperature limited by heat removal Power from 0.22 cm2 area, can scale further by increasing the area. Low-duty cycles increase peak power to nearly 1 kW from 5 × 5 mm area.
Spectral linewidth (1 TM) Several MHz Coupling of diode current fluctuations to cavity refractive index Can be reduced to the kHz range through use of an external cavity
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-7 Diode Lasers: Quantum Cascade (QCL)

Property Value Limit Reason Comments
Electrical efficiency (theory) Variable % Fundamental energy conservation Each laser transition efficiency limited by energy of photon divided by bandgap of base material, but multiple transitions in series (typ. 25-75) increase the efficiency by this factor.
Electrical efficiency (actual) 21 %, cw, RT, (40-50% pulsed, 160 K) Multiple device issues Ohmic losses, injected carrier spreading away from lasing region, absorption loss in active region, losses through the injector regions.
Wavelength = 4.9 µm.
Wavelength >3.8 µm (cw) Materials Limits to depth of quantum well in InP structures, but efficiency is low on the short-wavelength end. Pulsed operation to ~3 µm
<13 µm (cw) Materials Typical limit for room-temperature, cw operation. Pulsed/cryogenic operation to 30 µm
>60 µm cryogenics for cw THz Materials Phonon absorption in InP-based devices prevents coverage of 30-60-µm wavelengths,
Power Out Single device 5 W (4.9 µm) Thermal heating Achieved in high-efficiency (21%) devices
Spectral linewidth (1 TM) Sub-MHz Current and 1/f noise Can be reduced to the kHz range with current feedback. Intrinsic noise is several hundred Hz.

NOTE: Refer to Table C-2 for device properties as a function of semiconductor material system.

TABLE C-8 Diode Lasers: Interband Cascade (ICL)

Property Value Limit Reason Comments
Electrical efficiency (theory) Variable % Fundamental: energy conservation Eacc laser transition efficiency limited by the energy of the photon divided by the bandgap energy of the base semiconductor material, but ICLs employ multiple transitions in series so efficiency is increased
Electrical efficiency (actual) 15% (3.7 µm, cw, RT) Multiple device issues Ohmic losses, injected carrier spreading away from lasing region, absorption loss in active region, losses through the injector regions
Wavelength >3 µm, cw Materials Limited depth of interband quantum well
<6 µm cw Materials Too high current densities at longer wavelengths
Power out single device 0.36 W (3.7 µm) Thermal heating Achieved in high-efficiency (15%) devices

NOTE: Refer to Table C-2 for device properties as a function of semiconductor material system.

Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-9 Solid State Lasers: Bulk Format

Property Value Limit Reason Comments
Optical efficiency (theory) Quantum defect ≡ ratio of laser wavelength to average pump wavelength Fundamental: energy conservation Example: 76% for 1,064-nm Nd:YAG laser pumped at 808 nm. Violated when interaction between active ions allows >1 excited state per pump photon
Optical efficiency (actual) < quantum defect Multiple Poor spatial overlap of pump and lasing regions in material, incomplete absorption of pump, reflection of pump from material surface, losses in laser material, excited state absorption of pump or laser power, upconversion from upper laser level
Electrical efficiency (theory) Pump electrical efficiency times quantum defect Fundamental: Energy conservation Example: Pump diodes with 60% efficiency at 808 nm with Nd:YAG laser at 1,064 nm → 46% electrical efficiency
Electrical efficiency (actual) < pump electrical efficiency X quantum defect Multiple Optical efficiency < quantum defect; pump light loss in transport to laser material. Example: typical diode-pumped Nd:YAG lasers are 20-25% electrically efficient.
Wavelength >286 nm Materials Transparency of host crystal
Wavelength <7,150 nm Materials Long-wavelengths have multi-phonon decay, requires low-phonon hosts; may be impractical for high-power. Better hosts (e.g. YLF) can be used for <4,300-nm lasers
Average power (single device) 2 kW (rods) Material fracture, thermal effects 1,060-nm, diode-pumped systems. Higher powers with multiple active media: >100 kW is record (Nd:YAG). Yb:YAG used for thin disks
10 kW (disks)
15 kW (slabs)
Average power (1 device, diffraction-limited) 50 W (rods) Thermal distortion of laser material 1,060-nm region, diode-pumped systems. Higher powers possible with multiple active media, >100 kW is present record, using Nd:YAG slab. Yb:YAG used for thin disks
1 kW (disks)
15 kW (slabs)
Spectral linewidth (theory) Several Hz Fundamental: SchawlowTownes limit Set by spontaneous emission of gain medium into the laser mode. True for all lasers.
Spectral linewidth (actual, ms time scale) Several kHz Technical noise Fluctuations in optical cavity length from coupling between pump power and gain medium refractive index, acoustic noise, other cavity perturbations. External stabilization can reduce technical noise to the Hz level.
Spectral linewidth (long term) 10-50 MHz Environmental drift Slow change in laser cavity temperature
Mode-locked pulsewidth (theory) ∼3.5 fs Fundamental: laser material gain-bandwidth. Value is for Ti:sapphire at 800 nm, Cr:ZnSe is 7 fs at 2500 nm, Nd:YAG is 2 ps at 1,064 nm
Mode-locked pulsewidth (actual) ∼4.5 fs Ti-sapphire at 800 nm Dispersion in optical cavity, mirrors' spectral response, nonlinearities. Cr:ZnSe is around 50 fs
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-10 Solid State Lasers: Fiber Format

Property Value Limit Reason Comments
Optical efficiency (theory) Quantum defect = ratio of laser wavelength to average pump wavelength Fundamental: energy conservation Example: 95% for 1,030-nm Yb:fiber laser pumped at 976 nm. Violated for a few systems when interaction between active ions allows more than one excited state per pump photon
Optical efficiency (actual) < quantum defect: 88% slope efficiency for Yb:fiber Multiple Poor spatial overlap of pump and lasing regions in material, incomplete absorption of pump, losses in laser material, excited state absorption of pump or laser power, upconversion from upper laser level.
Electrical efficiency (theory) Pump electrical efficiency times quantum defect Fundamental: energy conservation Example: Pump diodes with 65% efficiency at 976 nm with Yb:fiber laser at 1,030 nm ->62% electrical efficiency
Electrical efficiency (actual) < above Multiple Actual optical efficiency lower than quantum defect, loss of pump light in transport from diode facet to pump cladding. Example: Yb:fiber at 1,030 nm -> 40% electrical efficiency
Wavelength >248 nm Materials Transparency limit of fiber (up-conversion laser operation in ZBLAN fibers
Wavelength <3,900 nm Materials Multi-phonon relaxation limits operation at longer wavelengths
Average power (single fiber, 1,000-nm) 20 kW Stimulated Raman scattering 1,030-nm Yb:fiber laser pumped by multiple 1,018-nm Yb:fiber lasers
Average power (single fiber, 2,000-nm) 1 kW Available pump power Tm:fiber laser pumped by 790-nm diode lasers
Average power (single fiber, 1 frequency, 1,000-nm) 100 W (5 kHz linewidth) Stimulated Brillouin scattering Yb:fiber lasers. Removed SBS by …
100-W result: thermal gradient along length of fiber.
1 kW (3 GHz linewidth)
1 kW result: frequency modulated source
Average power (single fiber, 1 frequency, 2,000-nm) 600 W (<5 MHz linewidth) Stimulated Brillouin scattering Tm:fiber laser
Peak power (single fiber, ns pulses) 0.45 MW (27 mJ in 60 ns) 4.5 MW (4.3 mJ; <1 ns) Simulated Raman scattering, optical breakdown Yb:silica, rod-type fibers. Flexible fibers typically generate 25 kW peak powers in 400 ns
Peak power (single fiber, ps range) 3.8 GW (2.2 mJ in 0.5 ps) Simulated Raman scattering, optical breakdown, self-phase modulation Yb:silica, employs chirped-pulse amplification (CPA) to avoid nonlinear effects, rod-type fibers. Flexible fibers with CPA operate around 100 MW of peak power
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-11 Nonlinear-Optics-Based Sources: Harmonic Generation

Property Value Limit Reason Comments
Conversion efficiency (theory) 100% Fundamental: Energy conservation For plane waves
Second-harmonic conversion efficiency (actual) 90% for flat-profile, high-energy beams (e.g., NIF) Multiple De-phasing from finite beam width and heating in crystal due to background and multi-photon absorption and creation of color centers, losses at entrance/exit faces, crystal, material imperfections, optical damage.
60-70% for Gaussian-profile beam
Third-harmonic conversion efficiency (actual) 90% for flat-profile, high-energy beams (e.g., NIF) Multiple De-phasing from finite beam width and heating in crystal due to background and multi-photon absorption and creation of color centers, losses at entrance/exit faces, crystal, material imperfections, optical damage.
50% for Gaussian-profile beam
Average power output (theory) Unlimited Process does not dissipate heat Nonlinear process has limited power density due to optical damage.
Average power output (actual) Widely variable Background, multi-photon and coating absorption, color-center formation. LBO material has the lowest absorption of common nonlinear materials, and is limited by absorption from coatings on the surface. Multiple hundreds of W for second-harmonic of Nd- or Yb-doped lasers.
Shortest wavelength, second harmonic 176 nm Phase-match, vanishing nonlinear coefficients 176 nm for KBBF crystals. For more readily available BBO crystals, about 205 nm
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×

TABLE C-12 Nonlinear-Optics-Based Sources: Optical Parametric Generation

Property Value Limit Reason Comments
Conversion efficiency from pump to signal + idler (theory) 100% Fundamental: energy conservation For plane waves
Conversion efficiency from pump to signal power Pump ÷ Signal wavelengths Fundamental: photon conservation (Manley-Rowe) For plane waves
Conversion efficiency from pump to idler power Pump ÷ Idler wavelengths Fundamental: photon conservation (Manley-Rowe) For plane waves
Conversion efficiency from pump to signal + idler (actual) 90% for cw 50% typical for pulsed Multiple De-phasing from finite beam size, de-phasing due to heating in crystal from background absorption or multi-photon absorption and creation of color centers, losses at entrance/exit faces, material imperfections, optical damage.
Buildup time reduces efficiency
Average-power output (theory) Unlimited Process does not dissipate heat Ultimate limit due to optical damage.
Average-power output (actual) Widely variable Absorption: from coatings, multiphotons, parasitics, color-center formation. See effects for conversion efficiency Levels currently below 100 W, but have been limited more by the pump laser power. Multiples of 100 W should be possible in near-IR with materials like LBO
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 287
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 288
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 289
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 290
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 291
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 292
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 293
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 294
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 295
Suggested Citation:"Appendix C: Laser Sources and Their Fundamental and Engineering Limits." National Research Council. 2014. Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing. Washington, DC: The National Academies Press. doi: 10.17226/18733.
×
Page 296
Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing Get This Book
×
Buy Paperback | $75.00 Buy Ebook | $59.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

In today's world, the range of technologies with the potential to threaten the security of U.S. military forces is extremely broad. These include developments in explosive materials, sensors, control systems, robotics, satellite systems, and computing power, to name just a few. Such technologies have not only enhanced the capabilities of U.S. military forces, but also offer enhanced offensive capabilities to potential adversaries - either directly through the development of more sophisticated weapons, or more indirectly through opportunities for interrupting the function of defensive U.S. military systems. Passive and active electro-optical (EO) sensing technologies are prime examples.

Laser Radar considers the potential of active EO technologies to create surprise; i.e., systems that use a source of visible or infrared light to interrogate a target in combination with sensitive detectors and processors to analyze the returned light. The addition of an interrogating light source to the system adds rich new phenomenologies that enable new capabilities to be explored. This report evaluates the fundamental, physical limits to active EO sensor technologies with potential military utility; identifies key technologies that may help overcome the impediments within a 5-10 year timeframe; considers the pros and cons of implementing each existing or emerging technology; and evaluates the potential uses of active EO sensing technologies, including 3D mapping and multi-discriminate laser radar technologies.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!