CPC Definition - Subclass H01S

Last Updated Version: 2019.01
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
Definition statement

This place covers:

Devices using stimulated emission, for the generation or amplification of coherent electromagnetic waves or other forms of wave energy, e.g. masers, lasers, X-ray lasers, gamma lasers, optical amplifiers.

Constructional details or arrangements, e.g. housings, packages, cooling, electrodes.

Configuration of the resonators, or shape of the active media.

Processes or apparatus for pumping (exciting) said devices.

Such functions as modulating, demodulating, frequency-changing, controlling, or stabilising of said coherent electromagnetic waves, insofar these functions are performed by elements being part of the optical resonators or amplifier's arrangements; this includes particularly:

  • Frequency multiplying, e.g. harmonic generation
  • Pulse-techniques, e.g. Q-switching, mode-locking, or gain-switching.

The special choice or adaptation of materials as active media.

Devices using non-linear amplification effects, e.g. stimulated Raman or Brillouin scattering

Relationships with other classification places

This subclass covers functions as modulating, demodulating, frequency-changing, controlling, or stabilising of coherent electromagnetic waves, insofar these functions are performed by elements being part of the optical resonators or amplifier's arrangements, e.g. inside-cavity harmonic generation. Said functions when performed outside the resonators or amplifier's arrangement, e.g. harmonic generation, are covered by subclass G02F.

With regard to the housing or package of a laser or maser, distinction is done between first and second level housing/packages.

A first level housing is considered to be the housing of the laser/maser directly enclosing the (cooled) device. An example for a first level housing is a semiconductor laser or a microlaser in a TO-can (H01S 5/022 and H01S 3/025).

A second level package or housing is considered to be a housing where this TO-can, for example, is integrated like a DVD recorder or a lamp or a beamer.

Second level packages are generally not covered by this subclass but should be in a subclass relating to the application of the device.

References
Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Eye surgery using laser

A61F 9/008

Radiation therapy using laser light

A61N 2005/067

Sintering by using laser light

B22F 3/105

Working by laser beam, e.g. welding, cutting or, boring

B23K 26/00

Joining of preformed parts by using laser light

B29C 65/16

Laser printers

B41J 2/44, B41J 2/455

Ring laser gyrometers; fibre laser gyrometers

G01C 19/66, G01C 19/72

Investigating or analysing colour or spectral properties of materials by using tunable lasers

G01N 21/39

Apparatus specially adapted for photomechanical, e.g. photolithographic, production of textured or patterned surfaces

G03F 7/20

Laser heads for recording or reproducing

G11B 7/125

Laser recording associated with non-optical reproducing, or laser reproducing associated with non-optical recording

G11B 11/00

Trimming by laser in the manufacture of resistors

H01C 17/242

Photolithographic processing on semiconductor bodies

H01L 21/027

Transmission systems employing light, e.g. all-optical repeaters

H04B 10/00, H04B 10/291 - H04B 10/299

Informative references

Attention is drawn to the following places, which may be of interest for search:

Lamps

F21K 9/00 - F21K 99/00

Measurements using light

G01C

Measurement of light

G01J 11/00

Optical spectroscopy

G01N 21/00

LIDAR

G01S 17/00

Coupling light guides with opto-electronic elements

G02B 6/42

Laser speckle optics

G02B 27/48

Control of light beams in general

G02F

Non-linear optics per se

G02F 1/35

Photolithography

G03F 7/00

Scanning

G06K 15/00

Semiconductor devices specially adapted for light emission

H01L 33/00

Reproduction

H04N 1/00

Displays

H04N 9/00

X-ray generation

H05G 2/00

Plasma generation

H05H 1/00

Special rules of classification

In H01S a document is classified according to the features disclosed, i.e. a similar strategy is applied as used for the F-terms of the Japanese patent documentation. Such features can be found, for example, in the figures depicting the embodiments and in the corresponding discussion of these figures in the description. Classification in H01S is not restricted to the wording of the claims or the summary of the invention. Even a detailed prior art device discussed into detail in the disclosure may be classified correspondingly.

In H01S it should be carefully distinguished between defining (e.g. H01S 3/08 or H01S 5/10), controlling (e.g. H01S 3/10 or H01S 5/06-H01S 5/065) and stabilising (e.g. H01S 3/13 or H01S 5/068). This is illustrated with the following example: A grating as one end mirror of the cavity of a laser defines and therefore fixes the wavelength of the laser. As long as it is not disclosed that this grating is intentionally rotated, such a grating will be classified as being a part of the resonator only, e.g. in H01S 3/08009 or in H01S 5/141. As soon as it is disclosed, that the grating is rotated to tune the wavelength, this is considered to fall under a wavelength control by a grating which is classified in H01S 3/1055, for example. When finally a feed-back loop is disclosed, e.g. with the help of a wavelength sensitive detector the intensity at a given wavelength is monitored and kept stable with the help of the feed-back loop, then a group in H01S 3/139 will be allocated. As however in the H01S 3/139 and sub-groups the nature of the wavelength defining reflector is not included, further classes in H01S 3/08 and sub-groups should be used to characterize the resonator details, e.g. the reflector being a grating and the number of resonator mirrors present.

This subclass does not cover light emitting devices where it is merely stated that they are a laser or maser, i.e. where the laser or maser is simply a "black box" without any specific details on the electromagnetic wave generation or feedback on it.

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

active medium

A medium providing for optical gain by the stimulated emission effect when excited by an excitation (pump) energy source.

laser

It is the acronym for "light amplification by stimulated emission of radiation" but it also refers, in broader sense, to any device using stimulated emission of radiation by excited atoms.Hence, for example, the expressions "semiconductor laser", "dye laser", "optical fibre laser" or "X-ray laser".

pumping

The process of providing the active medium for excitation energy.

Synonyms and Keywords

In patent documents, the following words/expressions are often used as synonyms:

  • active medium: gain medium, lasing medium excitation: pump(ing)

In patent documents, the word/expression in the first column is often used instead of the word/expression in the second column, which is used in the classification scheme of this place:

LASER

Light Amplification by Stimulated Emission of Radiation

MASER

Microwave Amplification By Stimulated Emission Of Radiation also known as Microwave Laser

EDFA

Erbium Doped Fibre Amplifier

SOA

Semiconductor Optical Amplifier

DBR Laser

Distributed Bragg Reflector Laser

DFB Laser

Distributed Feed-Back Laser

Masers, i.e. devices using stimulated emission of electromagnetic radiation in the microwave range
Definition statement

This place covers:

Masers, i.e. devices generating or amplifying light by stimulated emission from the infrared to the far-infrared/THz part of the electromagnetic wave spectrum, i.e. wavelengths longer than about 10 microns, e.g. CO2 laser.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Far-infrared and THz-lasers based on semiconductor lasers

H01S 5/00

Quantum cascade lasers with for example intra-band transitions

H01S 5/34

THz sources where stimulated emission is not explicitly involved, e.g. a fs-laser pulse illuminates an Auston switch or a Josephson contact and THz emission results from accelerating electrons according to the local amplitude of the applied electromagnetic field

G02F 1/35, H01L 31/00, H01Q

Gaseous {, i.e. beam masers}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Atomic clocks

G04F 5/14

Circuits using beam masers as a reference frequency for regulating frequency of oscillators

H03L 7/26

Molecular or atomic beam generation

H05H 3/02

Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range (semiconductors lasers H01S 5/00)
Definition statement

This place covers:

Devices generating or amplifying light by stimulated emission from the infrared to the ultraviolet part of the spectrum.

Laser media including gaseous, liquid and solid gain media as a matrix and comprising generally atoms, ions or molecules as dopants having discrete spectral absorption and emission lines or bands.

References
Limiting references

This place does not cover:

Semiconductor lasers

H01S 5/00

Informative references

Attention is drawn to the following places, which may be of interest for search:

Optical components for lasers per se are classified in the following groups/subclasses:

Laser crystal materials

C09K 11/00

Manufacturing of solid laser materials

C30B

Cooling means

F28F 3/00

Optical components like lenses, mirrors, gratings

G02B 1/00

Optical fibres

G02B 6/00

Linear and nonlinear optical components for control, modulation and frequency conversion of light

G02F 1/00

Constructional details {(housings or packages of fibre lasers H01S 3/06704)}
References
Limiting references

This place does not cover:

Housings or packages of fibre lasers

H01S 3/06704

of gas laser discharge tubes
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Gas discharge tubes in general

H01J 17/00, H01J 61/00

Optical devices within, or forming part of, the tube, e.g. windows, mirrors (reflectors having variable properties or positions for initial adjustment of the resonator H01S 3/086)
References
Limiting references

This place does not cover:

Reflectors having variable properties or position for initial adjustment of the resonator

H01S 3/086

Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube {(H01S 3/031 takes precedence)}
References
Limiting references

This place does not cover:

Metal vapour lasers

H01S 3/031

Informative references

Attention is drawn to the following places, which may be of interest for search:

Cooling arrangements for gas lasers

H01S 3/041

Gas dynamic lasers

H01S 3/0979

Means for obtaining or maintaining the desired gas pressure within the tube in general

H01J 17/22, H01J 61/24

{Non-homogeneous structure (H01S 3/07 takes precedence)}
Definition statement

This place covers:

Stepwise change of a dimension or a doping profile, e.g. undoped end caps on a doped laser rod or end flanges having a larger diameter than the part in between

References
Limiting references

This place does not cover:

Construction or shape of active medium consisting of a plurality of parts

H01S 3/07

{having a varying composition or cross-section in a specific direction}
Definition statement

This place covers:

Devices having a dopant gradient or a changing dimension of the laser crystal, i.e. there must a gradual change in the dopant profile or at least one of the laser material dimensions (e.g. tapering)

Fibre lasers
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Optical pumping thereof

H01S 3/094003

Controlling the output parameters

H01S 3/10

Stabilisation of the output parameters

H01S 3/13

Scattering effects, i.e. stimulated Brillouin or Raman effects

H01S 3/302

Optical fibres and packages comprising optical fibres

G02B 6/00

Transmission using light

H04B 10/00

Special rules of classification

Fibre lasers are not classified in H01S 3/0602-H01S 3/0627

As soon as details specific to amplification by stimulated emission are disclosed, a corresponding group in H01S 3/00 should be given, e.g. details on the amplification bandwidth, control or stabilisation of the fibre amplifier. The fact that for example merely a fibre amplifier is comprised by a device should not result in the allocation of a group in H01S 3/00.

{Fibre amplifiers (H01S 3/06708 takes precedence)}
References
Limiting references

This place does not cover:

Constructional details of the fibre

H01S 3/06708

Special rules of classification

Fibre amplifiers are generally not double classified by allocating in addition H01S 3/2308, only in the case of for example double passes etc. a respective coding in H01S 3/2325 and sub-groups is given.

Cascaded fibre amplifiers are only classified in H01S 3/06758 and not in H01S 3/2316.

consisting of a plurality of parts, e.g. segments (H01S 3/067 takes precedence)
References
Limiting references

This place does not cover:

Fibre lasers

H01S 3/067

Construction or shape of optical resonators or components thereof {(waveguide lasers H01S 3/063)}
References
Limiting references

This place does not cover:

Waveguide lasers

H01S 3/063

Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling the laser output

H01S 3/10

Stabilising

H01S 3/13

{Multiple-wavelength emission}
Definition statement

This place covers:

Laser generates having more than one laser wavelength, e.g. by internal frequency conversion

Outcoupling mirrors being at least partly transmissive for the at least two wavelengths, i.e. at least two laser beams at different wavelengths must be intentionally out-coupled

{Zig-zag travelling beam through the active medium}
Definition statement

This place covers:

Devices with multiple bounces off of lateral, non-end mirror surfaces

References
Limiting references

This place does not cover:

"Active mirror" lasers with a singly folded path through the laser medium,

H01S 3/0602, H01S 3/0619

defining a plurality of resonators, e.g. for mode selection {(single longitudinal mode control H01S 3/08022)}
References
Limiting references

This place does not cover:

Longitudinal mode control, e.g. specifically multimode

H01S 3/08022

Ring lasers {(fibre ring lasers H01S 3/06791)}
References
Limiting references

This place does not cover:

Fibre ring lasers

H01S 3/06791

Informative references

Attention is drawn to the following places, which may be of interest for search:

Ring laser gyrometers

G01C 19/66

One or more reflectors having variable properties or positions for initial adjustment of the resonator (varying a parameter of the laser output during operation H01S 3/10; stabilisation of the laser output H01S 3/13)
References
Limiting references

This place does not cover:

Varying a parameter of the laser output during operation

H01S 3/10

Stabilisation of the laser output

H01S 3/13

{Pulsed or modulated pumping (H01S 3/1024 takes precedence)}
Definition statement

This place covers:

Pulsed or modulated coherent pumping and no explicit effect of the pumping itself on a pulse forming, e.g. frequently Q-switched lasers are pumped in a pulsed way but the pulse duration is determined by the Q-switch and/or the resonator length and not the pumping means

References
Limiting references

This place does not cover:

Pulse generation

H01S 3/1024

of a laser diode
References
Limiting references

This place does not cover:

Details of laser diodes

H01S 5/00

using chemical or thermal pumping
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Generating plasma, e.g. by combustion

H02K 44/00, H05H 1/24

using pumping by high energy particles {(H01S 3/0903, H01S 3/0906, H01S 3/09707 take precedence)}
References
Limiting references

This place does not cover:

Free-electron laser

H01S 3/0903

Electrical, electrochemical, or electron-beam pumping of a dye laser

H01S 3/0906

Gas discharge using an electron or ion beam

H01S 3/09707

transversely excited (H01S 3/0975 takes precedence)
References
Limiting references

This place does not cover:

Gas discharge using inductive or capacitive excitation

H01S 3/0975

having auxiliary ionisation means {(H01S 3/09713 takes precedence)}
References
Limiting references

This place does not cover:

Auxiliary ionisation means for transversely excited lasers, e.g. double discharge excitation

H01S 3/09713

Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Controlling of light beams, frequency-changing, non-linear optics, optical logic elements, in general

G02F

Special rules of classification

Group H01S 3/10007 takes precedence over groups H01S 3/102 - H01S 3/104

{Pulse repetition rate control (H01S 3/11 takes precedence)}
Definition statement

This place covers:

Control as defined in the subclass H01S, i.e. the pulse repetition rate is controlled and not merely defined or fixed

References
Limiting references

This place does not cover:

Pulse generation, e.g. Q-switching, mode locking

H01S 3/11

Lasers provided with means to change the location from which, or the direction in which, laser radiation is emitted
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Optical-mechanical scanning systems in general

G02B 26/10

Electro-, magneto- or acousto-optical deflection

G02F 1/29

Control of position or direction of light beam generating device in general

G05D 3/00

by controlling the active medium, e.g. by controlling the processes or apparatus for excitation (H01S 3/13 takes precedence)
References
Limiting references

This place does not cover:

Stabilisation of laser output parameters, e.g. frequency, amplitude

H01S 3/13

{for pulse generation}
Definition statement

This place covers:

the control of the pulse duration by the intensity or the duration of the coherent or non-coherent pulsed pump source, i.e. the duration of the generated pulse is changed with pump intensity/duration,

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Details of laser diodes e.g. housing, cooling, electric circuitry

H01S 5/00

using a non-linear optical device, e.g. exhibiting Brillouin- or Raman-scattering {(mode locking using a non-linear element H01S 3/1112)}
References
Limiting references

This place does not cover:

Mode locking using a non-linear element

H01S 3/1112

{Pulse generation, e.g. Q-switching, mode locking}
Definition statement

This place covers:

Q-switching per se without any details of the kind of Q-switching

{characterised by a semiconducting matrix}
Definition statement

This place covers:

Devices with dopants in a bulk semiconductor matrix with discrete absorption / emission lines

{Ceramics}
Definition statement

This place covers:

Ceramic lasers

Special rules of classification

The solid laser material is additionally classified in H01S 3/163 and the doping in H01S 3/1601.

In the case a laser material is characterized by the (measured and depicted) amplification, H01S 3/2308 should be allocated besides the laser material and doping if appropriate.

amorphous, e.g. glass
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Glass manufacture, shaping or supplementary processes

C03B

Compositions for laserable glass

C03C 4/0071

Devices using stimulated emission of electromagnetic radiation in wave ranges other than those covered by groups H01S 1/00, H01S 3/00 or H01S 5/00, e.g. phonon masers, X-ray lasers or gamma-ray lasers
Definition statement

This place covers:

All devices generating or amplifying light by stimulated emission in spectral ranges with wavelengths longer than far-infrared/THz and shorter than ultraviolet.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

X-ray sources where for example a plasma is initiated by a focused femtosecond laser pulse which results in the generation of X-rays

H05G 2/00

Semiconductor lasers (superluminescent diodes {H01L 33/0045})
Definition statement

This place covers:

Semiconductor lasers which are characterized by having a valence and a conduction band with a band-gap in between and light emission due to a transition across at least part of a band-gap or within a band in the case of quantum cascade lasers. In order to tune the laser transition, the composition of the semiconductor and its doping can be designed.

One exception to this rule relates to "organic laser diodes". These devices have generally a layer structure similar to a laser diode comprising a semiconductor substrate and laminate, but the active region comprises an organic material.

Because it is frequently not disclosed whether the transition responsible for light emission is across a bandgap or in between discrete energy states, all such devices are classified in H01S 5/36 because the involvement of the semiconductor layers and the resonator structure being similar to that of a laser diode.

Relationships with other classification places

Semiconductor laser can be integrated with other electrical or optical components and has electrical circuitry for driving the laser diode. Details of such components per se are classified in for example the following main groups:

Optical components like lenses, mirrors, gratings

G02B 1/00

Optical fibres, packaging of semiconductor light sources and fibres

G02B 6/00

Beam manipulation and combination

G02B 26/00

Growth of semiconductors

H01L 21/02365

Cooling of semiconductors

H01L 23/34

Assemblies of semiconductors

H01L 25/00

Integration of semiconductors on a substrate

H01L 27/00

Photodiodes

H01L 31/00

Light emitting diodes (LED)

H01L 33/00

Organic light emitting devices (OLED)

H01L 51/50

Electrical circuits

H03K 3/00

Displays

H04N 9/00

References
Limiting references

This place does not cover:

Superluminescent diodes

H01L 33/0045

Informative references

Attention is drawn to the following places, which may be of interest for search:

Details of external cavity components; Control or stabilisation acting on laser components

H01S 3/08, H01S 3/10, H01S 3/13

Optical pumping by coherent light of a laser diode

H01S 3/0941

Mountings; Housings
Definition statement

This place covers:

First level packages, e.g. a laser diode in a TO can or a butterfly housing.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Packaging and electrical lead-through per se

H01L 23/00

Cooling arrangements {(H01S 5/0261 takes precedence)}
References
Limiting references

This place does not cover:

Non-optical elements

H01S 5/0261

Informative references

Attention is drawn to the following places, which may be of interest for search:

Cooling solid state junction devices

H01L 23/34

Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers (stabilisation of output H01S 5/06)
References
Limiting references

This place does not cover:

Stabilisation of output

H01S 5/06

Informative references

Attention is drawn to the following places, which may be of interest for search:

Coupling light guides with opto-electronic elements

G02B 6/42

Devices consisting of a plurality of semiconductor or other solid state components formed in or on a common substrate, adapted for light emission

H01L 27/15

Processes or apparatus for excitation, e.g. pumping, {e.g. by electron beams} (H01S 5/06 takes precedence)
References
Limiting references

This place does not cover:

Arrangements for controlling the laser output parameters

H01S 5/06

Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
Definition statement

This place covers:

Control/stabilisation by applying voltages to the electrodes of the semiconductor laser chip or temperature tuning of the laser diode itself;

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control/stabilisation of the external cavity elements

H01S 3/10, H01S 3/13

Transmission systems employing light

H04B 10/00

{comprising a non-linear region, e.g. generating harmonics of the laser frequency}
Definition statement

This place covers:

Frequency conversion inside the semiconductor laser chip

References
Limiting references

This place does not cover:

SHG in an external cavity is

H01S 3/109

by varying the potential of the electrodes (H01S 5/065 takes precedence)
References
Limiting references

This place does not cover:

Mode locking; Mode suppression; Mode selection; Self pulsating

H01S 5/065

Stabilisation of laser output parameters (H01S 5/0625 takes precedence)
References
Limiting references

This place does not cover:

Multi-section lasers

H01S 5/0625

{Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation}
Definition statement

This place covers:

Circuitry comprising diodes for overvoltage or surge protection

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Monolithic integration

H01S 5/0261

Construction or shape of the optical resonator {, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region (H01S 5/20 takes precedence)}
References
Limiting references

This place does not cover:

Structure or shape of the semi-conductor body to guide the optical wave; Confining structures perpendicular to the optical axis, e.g. index- or gain-guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers

H01S 5/20

{Waveguide having a modified shape along the axis, e.g. branched, curved, tapered, voids}
Definition statement

This place covers:

Structures of the laser diode chip (and its waveguide)

{Ring-lasers}
References
Limiting references

This place does not cover:

Laser diode with an external ring resonator for wavelength definition

H01S 5/14

the resonator having a periodic structure, e.g. in distributed feed-back [DFB] lasers (H01S 5/18 takes precedence)
References
Limiting references

This place does not cover:

Surface-emitting lasers

H01S 5/18

Informative references

Attention is drawn to the following places, which may be of interest for search:

Forward coupled structures, i.e. DFC lasers

H01S 5/1028

External cavity lasers {(external cavity elements, their control or stabilisation H01S 3/08, H01S 3/10 and H01S 3/13)}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

External cavity elements, their control or stabilisation

H01S 3/08, H01S 3/10, H01S 3/13

Special rules of classification

In this group external cavity elements correspond to elements inside the laser cavity but outside the monolithic semiconductor body. These elements correspond to intra cavity elements in H01S 3/00.

For external cavity lasers covered by H01S 5/14 the group H01S 5/06 is additionally allocated for the control/stabilisation by applying voltages to the electrodes of the semiconductor laser chip or temperature tuning of the laser diode itself.

Buried stripe structure {(H01S 5/227 takes precedence)}
References
Limiting references

This place does not cover:

Buried mesa structure; Striped active layer

H01S 5/227

{with a terraced structure}
Definition statement

This place covers:

Asymmetric protrusions comprised in the layer structure, i.e. only one step in the height of the substrate or the laminate,

comprising PN junctions, e.g. hetero- or double- heterostructures (H01S 5/34, H01S 5/36 take precedence)
References
Limiting references

This place does not cover:

The active region comprising quantum well, quantum wire, quantum box or supperlattice structures, e.g. single quantum well lasers (SQW lasers), multiple quantum well lasers (MQW lasers), graded index separate confinement hetrostructure lasers (GRINSCH lasers)

H01S 5/34

The active region comprising organic materials

H01S 5/36

{containing very small amounts, usually less than 1%, of an additional III or V compound to decrease the bandgap strongly in a non-linear way by the bowing effect}
Definition statement

This place covers:

Doping with small amounts of group III or V compounds

comprising quantum well or superlattice structures, e.g. single quantum well lasers [SQW-lasers], multiple quantum well lasers [MQW-lasers] or graded index separate confinement heterostructure lasers [GRINSCH-lasers] (H01S 5/36 takes precedence)
References
Limiting references

This place does not cover:

The active region comprising organic materials

H01S 5/36

in AIIIBV compounds, e.g. AlGaAs-laser {, InP-based laser}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Doping with small amounts of group III or V compounds

H01S 5/32358

comprising organic materials (dye lasers H01S 3/213)
References
Limiting references

This place does not cover:

Dye lasers

H01S 3/213

Arrangement of two or more semiconductor lasers, not provided for in groups H01S 5/02 - H01S 5/30 (H01S 5/50 takes precedence)
References
Limiting references

This place does not cover:

Structural details or components not essential to laser action

H01S 5/02

Processes or apparatus for excitation

H01S 5/04

Arrangements for controlling the laser output parameters

H01S 5/06

Construction or shape of the optical resonator

H01S 5/10

Structure or shape of the semi-conductor body to guide the optical wave; Confining structures perpendicular to the optical axis

H01S 5/20

Structure or shape of the active region; Materials used for the active region

H01S 5/30

Amplifier structures not provided for in groups H01S 5/02 - H01S 5/30

H01S 5/50

{Injection locking}
Definition statement

This place covers:

Master oscillator and (power) amplifier arrangements (MOPA), i.e. the wavelength of the amplifier is the same as of the laser diode acting as the oscillator

{Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S 5/42 takes precedence)}
Definition statement

This place covers:

Laser diode arrays / bars

References
Limiting references

This place does not cover:

Cooling of laser diode bars

H01S 5/024

Arrays of surface emitting lasers

H01S 5/42

{with an external cavity or using internal filters, e.g. Talbot filters}
Special rules of classification

External cavity lasers are additionally classified in group H01S 5/06 and sub-groups when the control/stabilisation by applying voltages to the electrodes of the semiconductor laser chip or temperature tuning of the laser diode itself is of interest.

Amplifier structures not provided for in groups H01S 5/02 - H01S 5/30
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Amplifier structures as repeaters in transmission systems

H04B 10/291