40.   FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS)

 41.	Electromagnetism; electron and ion optics

 41.20.-q	Electric, magnetic, and electromagnetic fields
 41.20.Bt	Maxwell equations, time-varying fields, conservation laws (see also 03.50.D Maxwell theory)
 41.20.Cv	Electrostatics; Poisson and Laplace equations, boundary-value problems
 41.20.Gz	Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems
 41.20.Jb	Electromagnetic wave propagation; radiowave propagation (for light propagation, see 42.25.B; for electromagnetic waves in plasma, see 52.35.H; for ionospheric and magnetospheric propagation, see 94.20.B and 94.30.T)

 41.50.+h	X-ray beams and x-ray optics (see also 07.85.F in instruments)

 41.60.-m	Radiation by moving charges
 41.60.Ap	Synchrotron radiation (for synchrotron radiation instrumentation, see 07.85.Q)
 41.60.Bq	Cherenkov radiation
 41.60.Cr	Free-electron lasers (see also 52.75.M Free-electron devices—in plasma physics)

 41.75.-i	Charged-particle beams
 41.75.Ak	Positive-ion beams
 41.75.Cn	Negative-ion beams
 41.75.Fr	Electron and positron beams
 41.75.Ht	Relativistic electron and positron beams
 41.75.Lx	Advanced accelerator concepts

 41.85.-p	Beam optics (see also 07.77 Atomic, molecular, and charged particle sources and detectors, 29.27 Beams in particle accelerators)
 41.85.Ar	Beam extraction, beam injection
 41.85.Ct	Beam shaping, beam splitting
 41.85.Ew	Beam profile, beam intensity
 41.85.Gy	Chromatic and geometrical aberrations
 41.85.Ja	Beam transport
 41.85.Lc	Beam focusing and bending magnets, wiggler magnets, and quadrupoles (see also 07.55.D—in instruments, for superconducting magnets, see 85.25.L)
 41.85.Ne	Electrostatic lenses, septa
 41.85.Qg	Beam analyzers, beam monitors, and Faraday cups
 41.85.Si	Beam collimators, monochromators

 41.90.+e	Other topics in electromagnetism; electron and ion optics

 42.	Optics (for optical properties of gases, see 51.70; for optical properties of bulk materials and thin films, see 78.20; for x-ray optics, see 41.50)

 42.15.-i	Geometrical optics
 42.15.Dp	Wave fronts and ray tracing
 42.15.Eq	Optical system design
 42.15.Fr	Aberrations
 42.15.Gs	Other topics in geometrical optics

 42.25.-p	Wave optics
 42.25.Bs	Wave propagation, transmission and absorption (see also 41.20.J—in electromagnetism; for propagation in atmosphere, see 42.68.A; see also 52.40.D, N—in plasma physics)
 42.25.Fx	Diffraction and scattering
 42.25.Gy	Edge and boundary effects; reflection and refraction
 42.25.Hz	Interference
 42.25.Ja	Polarization
 42.25.Kb	Coherence
 42.25.Lc	Birefringence
 42.25.Md	Other topics in wave optics

 42.30.-d	Imaging and optical processing
 42.30.Kq	Fourier optics
 42.30.Lr	Modulation and optical transfer functions
 42.30.Ms	Speckle and moire patterns
 42.30.Rx	Phase retrieval
 42.30.Sy	Pattern recognition
 42.30.Tz	Computer vision; robotic vision
 42.30.Va	Image forming and processing
 42.30.Wb	Image reconstruction; tomography
 42.30.Yc	Other topics in imaging and optical processing

 42.40.-i	Holography
 42.40.Eq	Holographic optical elements; holographic gratings
 42.40.Ht	Hologram recording and read-out methods (see also 42.70.L Holographic recording materials; optical storage media)
 42.40.Jv	Computer-generated holograms
 42.40.Kw	Holographic interferometry; other holographic techniques (see also 07.60.L Interferometers)
 42.40.Lx	Diffraction efficiency, resolution, and other hologram characteristics
 42.40.My	Applications
 42.40.Pa	Volume holograms

 42.50.-p	Quantum optics (for lasers, see 42.55 and 42.60; see also 42.65 Nonlinear optics, 03.65 Quantum mechanics)
 42.50.Ar	Photon statistics and coherence theory
 42.50.Ct	Quantum description of interaction of light and matter; related experiments
 42.50.Dv	Nonclassical field states; squeezed, antibunched, and sub-Poissonian states; operational definitions of the phase of the field; phase measurements
 42.50.Fx	Cooperative phenomena; superradiance and superfluorescence
 42.50.Gy	Effects of atomic coherence on propagation, absorption, and amplification of light
 42.50.Hz	Strong-field excitation of optical transitions in quantum systems; multi-photon processes; dynamic Stark shift (for multiphoton ionization and excitation of atoms and molecules, see 32.80.R, and 33.80.R, respectively)
 42.50.Lc	Quantum fluctuations, quantum noise, and quantum jumps
 42.50.Md	Optical transient phenomena: quantum beats, photon echo, free-induction decay, dephasings and revivals, optical nutation, and self-induced transparency
           	Dynamics of nonlinear optical systems; optical instabilities, optical chaos, and optical spatio–temporal dynamics, see 42.65.S
           	Optical solitons; nonlinear guided waves, see 42.65.T
 42.50.Vk	Mechanical effects of light on atoms, molecules, electrons, and ions (see also 32.80.P and 33.80.P Optical cooling and trapping of atoms and molecules, respectively)

           	Optical tests of fundamental laws and forces, see 12.20.F Experimental tests in quantum electrodynamics and 03.65.B Theory of measurements in quantum mechanics

 42.55.-f	Lasers
 42.55.Ah	General laser theory
 42.55.Ks	Chemical lasers (for chemical laser kinetics, see 82.40.T)
 42.55.Lt	Gas lasers including excimer and metal-vapor lasers
 42.55.Mv	Dye lasers
 42.55.Px	Semiconductor lasers; laser diodes
 42.55.Rz	Doped-insulator lasers and other solid state lasers
 42.55.Sa	Microcavity and microdisk lasers
 42.55.Vc	X- and  -ray lasers
 42.55.Wd	Fiber lasers
 42.55.Xi	Diode-pumped lasers
 42.55.Ye	Raman lasers (see also 42.65.D Stimulated Raman scattering; CARS)
           	Free-electron lasers, see 41.60.C

 42.60.-v	Laser optical systems: design and operation
 42.60.By	Design of specific laser systems
 42.60.Da	Resonators, cavities, amplifiers, arrays, and rings
 42.60.Fc	Modulation, tuning, and mode locking
 42.60.Gd	Q-switching
 42.60.Jf	Beam characteristics: profile, intensity, and power; spatial pattern formation
 42.60.Lh	Efficiency, stability, gain, and other operational parameters
 42.60.Mi	Dynamical laser instabilities; noisy laser behavior
 42.60.Pk	Continuous operation
 42.60.Rn	Relaxation oscillations and long pulse operation

           	Ultrashort pulse generation, see 42.65.T

           	Dynamics of nonlinear optical systems, see 42.65.S

 42.62.-b	Laser applications
 42.62.Be	Biological and medical applications
 42.62.Cf	Industrial applications
 42.62.Eh	Metrological applications (see also 06.20 Metrology, and 06.30 Measurements common to several branches of physics and astronomy)
 42.62.Fi	Laser spectroscopy
 42.62.Hk	Other applications

 42.65.-k	Nonlinear optics
 42.65.An	Optical susceptibility, hyperpolarizability (see also 33.15.M Electric and magnetic moments, polarizability and magnetic susceptibility of molecules)
 42.65.Dr	Stimulated Raman scattering; CARS
 42.65.Es	Stimulated Brillouin and Rayleigh scattering
 42.65.Hw	Phase conjugation, optical mixing, and photorefractive effect
 42.65.Jx	Beam trapping, self-focusing, and thermal blooming
 42.65.Ky	Harmonic generation, frequency conversion (see also 42.79.N Optical frequency converters)
 42.65.Pc	Optical bistability, multistability, and switching (see also 42.60.G Q-switching; 42.79.T Optical computers, logic elements, interconnects, switches; neural networks)
 42.65.Re	Ultrafast processes; optical pulse generation and pulse compression
 42.65.Sf	Dynamics of nonlinear optical systems; optical instabilities, optical chaos and complexity, and optical spatio–temporal dynamics
 42.65.Tg	Optical solitons; nonlinear guided waves (for solitons in fibers, see 42.81.D)
 42.65.Vh	Other nonlinear optical phenomena
 42.65.Wi	Nonlinear waveguides
 42.65.Yj	Optical parametric oscillators and amplifiers

 42.66.-p	Physiological optics
 42.66.Ct	Anatomy and optics of eye
 42.66.Ew	Physiology of eye; optic-nerve structure and function
 42.66.Lc	Vision: light detection, adaptation, and discrimination
 42.66.Ne	Color vision: color detection, adaptation, and discrimination
 42.66.Qg	Scales for light and color detection
 42.66.Si	Psychophysics of vision, visual perception; binocular vision

 42.68.-w	Atmospheric optics
 42.68.Ay	Propagation, transmission, attenuation, and radiative transfer (see also 92.60.T Interaction of atmosphere with electromagnetic waves; propagation)
 42.68.Bz	Atmospheric turbulence effects (see also 92.60.E Convection, turbulence, and diffusion)
 42.68.Ca	Spectral absorption by atmospheric gases (see also 94.10.G Absorption and scattering of radiation)
 42.68.Ge	Effects of clouds and water (see also 92.60.J Water in the atmosphere; 92.60.N Cloud physics)
 42.68.Jg	Effects of aerosols (see also 92.60.M Particles and aerosols)
 42.68.Kh	Effects of air pollution (see also 92.60.S Air quality and air pollution)
 42.68.Mj	Scattering, polarization (see also 94.10.G Absorption and scattering of radiation)
 42.68.Sq	Image transmission and formation
 42.68.Wt	Remote sensing; LIDAR and adaptive systems

 42.70.-a	Optical materials (see also 81.05 specific materials: fabrication, treatment, testing and analysis)
 42.70.Ce	Glasses, quartz
 42.70.Df	Liquid crystals (for structure of liquid crystals, see 61.30)
 42.70.Gi	Light-sensitive materials
 42.70.Hj	Laser materials
 42.70.Jk	Polymers and organics
 42.70.Km	Infrared transmitting materials
 42.70.Ln	Holographic recording materials; optical storage media
 42.70.Mp	Nonlinear optical crystals (see also 77.84 Dielectric, piezoelectric, and ferroelectric materials)
 42.70.Nq	Other nonlinear optical materials; photorefractive and semiconductor materials
 42.70.Qs	Photonic bandgap materials

 42.72.-g	Optical sources and standards (for lasers, see 42.55; see also 07.57.H in instruments)
 42.72.Ai	Infrared sources
 42.72.Bj	Visible and ultraviolet sources

 42.79.-e	Optical elements, devices, and systems (for integrated optics, see 42.82; for fiber optics, see 42.81)
           	Optical instruments, equipment and techniques, see 07.60 and 07.57
           	Optical spectrometers, see 07.57.T and 07.60.R
           	Photography, photographic instruments and techniques, see 07.68
           	Magnetooptical devices, see 85.70.S
 42.79.Ag	Apertures, collimators
 42.79.Bh	Lenses, prisms and mirrors
 42.79.Ci	Filters, zone plates, and polarizers
 42.79.Dj	Gratings (for holographic gratings, see 42.40.E)
 42.79.Ek	Solar collectors and concentrators (see also 84.60.J Photoelectric conversion: solar cells and arrays)
 42.79.Fm	Reflectors, beam splitters, and deflectors
 42.79.Gn	Optical waveguides and couplers (for fiber waveguides and waveguides in integrated optics, see 42.81.Q and 42.82.E, respectively)
 42.79.Hp	Optical processors, correlators, and modulators
 42.79.Jq	Acousto-optical devices (see also 43.38.Z—in acoustics appendix)
 42.79.Kr	Display devices, liquid-crystal devices (see also 85.60.P Display systems)
 42.79.Ls	Scanners, image intensifiers, and image converters (see also 85.60 Optoelectronic devices)
 42.79.Mt	Schlieren devices
 42.79.Nv	Optical frequency converters
 42.79.Pw	Imaging detectors and sensors (see also 85.60.G Photodetectors)
 42.79.Qx	Range finders, remote sensing devices; laser Doppler velocimeters, SAR, and LIDAR (see also 42.68.W Remote sensing; LIDAR and adaptive systems)
 42.79.Ry	Gradient-index (GRIN) devices (for fiber GRIN devices, see 42.81.H)
 42.79.Sz	Optical communication systems, multiplexers, and demultiplexers
 42.79.Ta	Optical computers, logic elements, interconnects, switches; neural networks
 42.79.Vb	Optical storage systems, optical disks (see also 42.40.H Hologram recording and readout methods)
 42.79.Wc	Optical coatings
 42.79.Yd	Other optical elements, devices, and systems

 42.81.-i	Fiber optics
           	Fiber-optic instruments, see 07.60.V
 42.81.Bm	Fabrication, cladding, and splicing
 42.81.Cn	Fiber testing and measurement of fiber parameters
 42.81.Dp	Propagation, scattering, and losses; solitons
 42.81.Gs	Birefringence, polarization
 42.81.Ht	Gradient-index (GRIN) fiber devices
 42.81.Pa	Sensors, gyros
 42.81.Qb	Fiber waveguides, couplers, and arrays
 42.81.Wg	Other fiber-optical devices (for fiber lasers, see 42.55.W)

 42.82.-m	Integrated optics
 42.82.Bq	Design and performance testing of integrated-optical systems
 42.82.Cr	Fabrication techniques; lithography, pattern transfer (see also 85.40 Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology)
 42.82.Ds	Interconnects, including holographic interconnects (see also 42.79.T Optical computers, logic elements, interconnects, switches; neural networks)
 42.82.Et	Waveguides, couplers, and arrays (for fiber waveguides, see 42.81.Q)
 42.82.Fv	Hybrid systems
 42.82.Gw	Other integrated-optical elements and systems

 42.86.+b	Optical workshop techniques

 42.87.-d	Optical testing techniques
 42.87.Bg	Phase shifting interferometry (see also 07.60.L Interferometers)
 42.87.Ch	Other optical testing techniques

 42.88.+h	Radiation effects on optical elements, devices, and systems

 42.90.+m	Other topics in optics

 43.	Acoustics (for more detailed headings, see Appendix to 43)

 43.20.+g	General linear acoustics (see also 03.40.K Waves and wave propagation: general mathematical aspects)

 43.25.+y	Nonlinear acoustics, macrosonics

 43.28.+h	Aeroacoustics, atmospheric sound (see also 92.60 Meteorology)

 43.30.+m	Underwater sound (see also 92.10.V—in physics of oceans)

 43.35.+d	Ultrasonics, quantum acoustics, and physical effects of sound

           	Phonons in crystal lattices, see 63.20

           	Acoustical properties of rocks and minerals, see 91.60.L

           	Sound waves in plasma, see 52.35.D

           	Low-temperature acoustics and sound in liquid helium, see 67

           	Acoustical properties of solids, see 62.65; for ultrasonic relaxation, see 62.80

           	Acoustic properties of thin films, see 68.60.B

           	Surface waves in liquids and solids, see 68.10 and 68.35.G

           	Acoustoelectric effects, see 72.50 and 73.50.R

           	Magnetoacoustic effects, oscillations, and resonance, see 72.55, 73.50.R, and 75.80

           	Acoustic holography, see 43.60; for acoustooptical effects, see 78.20.H

 43.38.+n	Transduction; acoustical devices for the generation and reproduction of sound

 43.40.+s	Structural acoustics and vibration

 43.50.+y	Noise: its effects and control

 43.55.+p	Architectural acoustics

 43.58.+z	Acoustical measurements and instrumentation

 43.60.+d	Acoustic signal processing

 43.64.+r	Physiological acoustics

           	Biological effects of sound and ultrasound, see 87.51

 43.66.+y	Psychological acoustics

 43.70.+i	Speech production

 43.71.+m	Speech perception

 43.72.+q	Speech processing and communication systems

 43.75.+a	Music and musical instruments

 43.80.+p	Bioacoustics

 43.90.+v	Other topics in acoustics

 44.	Heat transfer, thermal and thermodynamic processes

 44.10.+i	Heat conduction (models, phenomenological description)

 44.25.+f	Convective and constrained heat transfer (see also 47.27.T Convection and heat transfer)

 44.30.+v	Heat transfer in inhomogeneous media, in porous media, and through interfaces

 44.40.+a	Radiative heat transfer

 44.50.+f	Thermal properties of matter (phenomenology, experimental techniques)

 44.60.+k	Thermodynamic processes (phenomenology, experimental techniques)

 44.90.+c	Other topics in heat transfer, thermal and thermodynamic processes

 46.	Classical mechanics (for mechanical properties of condensed matter, see 62; for rheology, see 83)

 46.10.+z	Mechanics of discrete systems (see also 03.20—general mathematical aspects, 95.10.C Celestial mechanics)

           	Continuum mechanics, see 83.10.F

 46.30.-i	Structural mechanics of shells, plates, and beams
 46.30.Cn	Static elasticity
 46.30.Lx	Static buckling and instability
 46.30.My	Vibrations, aeroelasticity, hydroelasticity, mechanical waves, and shocks
 46.30.Nz	Fracture mechanics, fatigue, and cracks
 46.30.Pa	Friction, wear, adherence, hardness, mechanical contacts, and tribology (see also 81.40.P—in materials science)
 46.30.Rc	Measurement methods and techniques

 46.90.+s	Other topics in classical mechanics

 47.	Fluid dynamics (for fluid dynamics of quantum fluids, see 67; see also 83 Rheology; for sound generation by fluid flow, see 43.28.R in acoustics appendix)

 47.10.+g	General theory (see also 03.40.G—in classical mechanics of continuous media, 83.10—in rheology)

 47.11.+j	Computational methods in fluid dynamics (see also 83.85.P Flow computation—in rheology; 02.70—in mathematical methods in physics)

 47.15.-x	Laminar flows
 47.15.Cb	Laminar boundary layers
 47.15.Fe	Stability of laminar flows
 47.15.Gf	Low-Reynolds-number (creeping) flows
 47.15.Hg	Potential flows
 47.15.Ki	Inviscid flows with vorticity
 47.15.Pn	Laminar suspensions
 47.15.Rq	Laminar flows in cavities

 47.17.+e	Mechanical properties of fluids (see also 62.10 Mechanical properties of liquids)

 47.20.-k	Hydrodynamic stability
 47.20.Bp	Buoyancy-driven instability
 47.20.Cq	Inviscid instability
 47.20.Dr	Surface-tension-driven instability
 47.20.Ft	Instability of shear flows
 47.20.Gv	Viscous instability
 47.20.Hw	Morphological instability; phase changes (see also 64 Equations of state, phase equilibria, and phase transitions)
 47.20.Ky	Nonlinearity (including bifurcation theory)
 47.20.Lz	Secondary instability
 47.20.Ma	Interfacial instability
 47.20.Pc	Receptivity
           	Chaotic phenomena, see 47.52 and 05.45

 47.27.-i	Turbulent flows, convection, and heat transfer
 47.27.Ak	Fundamentals
 47.27.Cn	Transition to turbulence
 47.27.Eq	Turbulence simulation and modeling
 47.27.Gs	Isotropic turbulence; homogeneous turbulence
 47.27.Jv	High-Reynolds-number turbulence
 47.27.Lx	Wall-bounded thin shear flows
 47.27.Nz	Boundary layer and shear turbulence
 47.27.Pa	Thick shear flows
 47.27.Qb	Turbulent diffusion
 47.27.Rc	Turbulence control
 47.27.Sd	Noise (turbulence generated)
 47.27.Te	Convection and heat transfer (see also 44.25 in heat transfer, thermal and thermodynamic processes)
 47.27.Vf	Wakes
 47.27.Wg	Jets

 47.32.-y	Rotational flow and vorticity
 47.32.Cc	Vortex dynamics
 47.32.Ff	Separated flows

 47.35.+i	Hydrodynamic waves

 47.37.+q	Hydrodynamic aspects of superfluidity (see also 67.40.H and 67.57.D—in quantum fluids and solids)

 47.40.-x	Compressible flows; shock and detonation phenomena (see also 28.70 Nuclear explosions, 52.35.T Shock waves in plasma, 83.50.T—in rheology, 43.25.C, 43.28.M and 43.40.J—in acoustics appendix)
 47.40.Dc	General subsonic flows
 47.40.Hg	Transonic flows
 47.40.Ki	Supersonic and hypersonic flows
 47.40.Nm	Shock-wave interactions and shock effects (for shock-wave initiated chemical reactions, see 82.40.F)

 47.45.-n	Rarefied gas dynamics
 47.45.Dt	Free molecular flows
 47.45.Gx	Slip flows
 47.45.Nd	Accommodation

 47.50.+d	Non-Newtonian fluid flows (see also 83.50 Deformation, material flow)

 47.52.+j	Chaos (see also 05.45 Theoretical models of chaotic systems; 83.50.W Chaotic flows; drag reduction)

 47.53.+n	Fractals

 47.54.+r	Pattern selection; pattern formation

 47.55.-t	Nonhomogeneous flows
 47.55.Bx	Cavitation
 47.55.Dz	Drops and bubbles
 47.55.Hd	Stratified flows
           	Rotational flows, see 47.32
 47.55.Kf	Multiphase and particle-laden flows
 47.55.Mh	Flows through porous media (for heat transfer in porous media, see 44.30)

 47.60.+i	Flows in ducts, channels, nozzles, and conduits (see also 83.10 and 83.50—in rheology)

           	Biological fluid dynamics, see 87.45

 47.62.+q	Flow control

 47.65.+a	Magnetohydrodynamics and electrohydrodynamics (for MHD in plasma, see 52.30)

 47.70.-n	Reactive, radiative, or nonequilibrium flows
 47.70.Fw	Chemically reactive flows (see also 83.80.J Chemically reactive materials—in rheology)
 47.70.Mc	Radiation gas dynamics
 47.70.Nd	Nonequilibrium gas dynamics

 47.75.+f	Relativistic fluid dynamics (for astrophysical aspects, see 95.30.L and 95.30.Q)

 47.80.+v	Instrumentation for fluid dynamics (see also 83.85—in rheology; 07.30 Vacuum apparatus and techniques)

 47.90.+a	Other topics in fluid dynamics