CN106461874A - Array waveguide grating and tunable laser having same - Google Patents

Array waveguide grating and tunable laser having same Download PDF

Info

Publication number
CN106461874A
CN106461874A CN201480077957.4A CN201480077957A CN106461874A CN 106461874 A CN106461874 A CN 106461874A CN 201480077957 A CN201480077957 A CN 201480077957A CN 106461874 A CN106461874 A CN 106461874A
Authority
CN
China
Prior art keywords
waveguides
arrayed waveguide
waveguide grating
reflective
tunable laser
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201480077957.4A
Other languages
Chinese (zh)
Other versions
CN106461874B (en
Inventor
高磊
王寅
曹权
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of CN106461874A publication Critical patent/CN106461874A/en
Application granted granted Critical
Publication of CN106461874B publication Critical patent/CN106461874B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/34—Optical coupling means utilising prism or grating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Integrated Circuits (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

An array waveguide grating (AWG) (30) and tunable laser (1000) having the same; the AWG (30) comprises an input coupler (31), a first array waveguide area (33) and a second array waveguide area (34); the first array waveguide area (33) comprises a plurality of first waveguides (331), and the neighboring first waveguides (331) have a first optical path difference; the second array waveguide area (34) comprises a plurality of second waveguides (341), and the neighboring second waveguides (341) have a second optical path difference, and the first optical path difference is not equal to the second optical path difference.

Description

Array waveguide grating and tunable laser with same Technical Field
The invention relates to the field of optical communication, in particular to an arrayed waveguide grating and a tunable laser with the arrayed waveguide grating.
Background
The development trend of optical communication is high-capacity high-speed optical transmission and more flexible optical network structure. Currently, the 100G technology using high-order modulation and coherent reception has entered into the commercial stage and is one of the trends in the industry. With the deployment of a 100G coherent system, the optical module of the first generation standard cannot meet the use requirements in terms of size, power consumption and other performance, and has become a bottleneck for improving the integration density of the optical module, so that it has an important significance to develop an optical module with miniaturization and low power consumption.
One existing solution is to use a planar optical waveguide technology to fabricate core optical devices in an optical module, such as a laser, a modulator, and a receiver, so as to achieve miniaturization and low power consumption. Among them, tunable lasers based on planar optical waveguide technology are one of the key technologies. Currently, several tunable lasers based on planar optical waveguide technology, such as those based on Arrayed Waveguide Grating (AWG) structure, have been developed in the industry. However, most of these tunable lasers have the problems of high requirements for manufacturing processes, high manufacturing cost, difficulty in realizing continuous tuning of wavelengths, limited tuning range, and the like, and cannot meet the use requirements.
Disclosure of Invention
In view of the above, an object of the present invention is to provide an arrayed waveguide grating and a tunable laser having the same, where the tunable laser can be fabricated on a planar optical waveguide and has the advantages of high integration level, simple fabrication process, and wide wavelength tunable range.
In a first aspect, an arrayed waveguide grating is provided, which includes an input coupler, a first arrayed waveguide region and a second arrayed waveguide region, where the first arrayed waveguide region includes a plurality of first waveguides, and the adjacent first waveguides have a first optical path difference, the second arrayed waveguide region includes a plurality of second waveguides, and the adjacent second waveguides have a second optical path difference, where the first optical path difference is not equal to the second optical path difference.
In a first possible implementation manner of the first aspect, the arrayed waveguide grating further includes a first electrode, the first electrode is electrically connected to the plurality of first waveguides, and the first electrode is configured to apply a voltage to the plurality of first waveguides to modulate the first optical path difference.
In a second possible implementation manner of the first aspect, the arrayed waveguide grating further includes a second electrode, the second electrode is electrically connected to the second waveguides, and the second electrode is configured to apply a voltage to the second waveguides to modulate the second optical path difference.
In a second aspect, a tunable laser is provided, which includes a reflective element, a reflective transmissive element, a gain medium, and the arrayed waveguide grating, where the arrayed waveguide grating and the gain medium are disposed between the reflective element and the reflective transmissive element.
In a first possible implementation manner of the second aspect, one end of each of the first waveguides and the second waveguides of the arrayed waveguide grating is disposed on the reflective element, and the other end of each of the first waveguides and the second waveguides is coupled to the input coupler, the first light beam is distributed to the first waveguides and the second waveguides through the input coupler, is transmitted, and is reflected by the reflective element to the input coupler to generate the second light beam, and the input coupler outputs the second light beam.
In a second possible implementation manner of the second aspect, the reflective element is constituted by a waveguide type reflective structure integrated on the plurality of first waveguides and the plurality of second waveguides.
In a third possible implementation manner of the second aspect, the arrayed waveguide grating further includes an output coupler, and one end of each of the plurality of first waveguides and the plurality of second waveguides of the arrayed waveguide grating is coupled to the output coupler, and the other end of each of the plurality of first waveguides and the plurality of second waveguides is coupled to the input coupler.
In a fourth possible implementation form of the second aspect, the tunable laser further comprises a phase modulator disposed between the reflective element and the reflective transmissive element.
In a fifth possible implementation manner of the second aspect, the phase modulator is obtained by covering a metal electrode on the first planar optical waveguide, and changing a refractive index of the first planar optical waveguide by applying a current on the metal electrode; alternatively, the first and second electrodes may be,
the phase modulator is obtained by covering the first planar optical waveguide with a metal electrode, and by applying a current to the metal electrode to change the refractive index of a predetermined phase modulating material doped and formed on the phase modulator.
In a sixth possible implementation manner of the second aspect, the tunable laser further includes a second planar optical waveguide, the gain medium and the reflective element are fabricated on the second planar optical waveguide, and the arrayed waveguide grating, the phase modulator, and the reflective and transmissive element are fabricated on the first planar optical waveguide; alternatively, the first and second electrodes may be,
the gain medium and the reflection and transmission element are manufactured on the second plane optical waveguide, and the arrayed waveguide grating, the phase modulator and the reflection element are manufactured on the first plane optical waveguide.
In a seventh possible implementation manner of the second aspect, a lens is disposed between the first planar optical waveguide and the second planar optical waveguide.
The tunable laser provided by the embodiment of the invention realizes the mode selection of the input first light beam by designing the waveguide array grating with two different optical path differences so as to output a second light beam only containing one wavelength, and the wavelength of the second light beam can be adjusted by covering the first electrode and the second electrode on the waveguide array grating, so that the effect of continuously adjusting the wavelength is realized. The tunable laser provided by the invention can be integrally manufactured on a planar optical waveguide, so that the tunable laser has the advantages of high integration level, small volume, large wavelength adjustment range, low requirements on process manufacturing and the like, and meets the use requirements of high-capacity and high-speed optical transmission and new-generation optical devices.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a tunable laser according to a first embodiment of the present invention.
Fig. 2 is a schematic structural view of the arrayed waveguide grating shown in fig. 1.
Fig. 3 is a schematic block diagram of the arrayed waveguide grating shown in fig. 1.
Fig. 4 is a schematic diagram of transmission peaks of the arrayed waveguide grating under different optical path differences.
FIG. 5 is a schematic illustration of coincident transmission peaks of the output of an arrayed waveguide grating of an embodiment of the invention.
Fig. 6 is another schematic diagram of the tunable laser shown in fig. 1.
Fig. 7 is a schematic structural diagram of a tunable laser according to a second embodiment of the present invention.
Fig. 8 is a schematic structural diagram of a tunable laser according to a third embodiment of the present invention.
Fig. 9 is a schematic structural diagram of a tunable laser according to a fourth embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a tunable laser 1000 according to a first embodiment of the present invention, which can be fabricated in a first planar optical waveguide 100. The tunable laser 1000 includes a reflective element 10, a reflective transmissive element 20, an Arrayed Waveguide Grating (AWG) 30, and a gain medium 40. The reflective element 10, the reflective and transmissive element 20, the arrayed waveguide grating 30, and the gain medium 40 may be obtained in different regions of the first planar optical waveguide 100 by etching, photolithography, doping, cleaving, plating, or ion implantation.
In the embodiment of the present invention, the reflective element 10 and the reflective-transmissive element 20 form a resonant cavity, and the arrayed waveguide grating 30 and the gain medium 40 are disposed in the resonant cavity. The arrayed waveguide grating 30 is disposed between the reflective element 10 and the reflective-transmissive element 20, and the gain medium 40 is disposed between the reflective element 10 and the arrayed waveguide grating 30. The gain medium 40 emits a first light beam comprising a plurality of wavelengths (or a succession of wavelengths) under the pump of a pump source. The first light beam is incident into the arrayed waveguide grating 30, the arrayed waveguide grating 30 demultiplexes (or filters) the first light beam to output a second light beam with only one wavelength, and the wavelength of the output second light beam can be adjusted by adjusting the waveguide refractive index of the arrayed waveguide grating 30. The second light beam propagates back and forth in the resonant cavity formed by the reflective element 10 and the transmissive element 20, and passes through the arrayed waveguide grating 30 and the gain medium 40 during propagation. When the second light beam simultaneously satisfies the amplitude condition and the phase condition of the oscillation in the resonant cavity, the second light beam can be stably transmitted in the resonant cavity. Wherein the amplitude condition requires that the gain of the second beam (gain generated by gain medium 40, and the second beam passing through the gain medium 40, due to stimulated radiation effect, the gain medium 40 generates laser light with the frequency and phase of the second beam, so that gain can be obtained for the second beam) of the second beam to and fro once in the resonant cavity is not less than the loss (the loss includes the loss generated by the transmission of the second beam in reflective element 10 and reflective transmissive element 20, the loss generated by the second beam in the resonant cavity due to scattering, diffraction, and other absorption losses). Wherein the light transmitted by the second light beam at the reflective and transmissive element 20 is output light. The phase condition requires that the phase change of the second light beam which makes one round trip in the resonant cavity is integral multiple of 2 pi.
In the embodiment of the present invention, the reflective element 10 can be obtained by cleaving an end surface of the first planar optical waveguide 100 (the property that a mineral crystal is broken in a certain direction after being stressed and a smooth plane is generated is referred to as cleavage, and the end surface is a smooth plane), and has high reflectivity for the second light beam. In order to make the reflective element 10 have a higher reflectivity for the second light beam, a reflective film may be further coated on the cleaved end surface, so as to ensure that a larger portion of the second light beam is reflected on the reflective element 10. Accordingly, the reflective-transmissive element 20 can also be obtained by cleaving the other end surface of the first planar optical waveguide 100 opposite to the reflective element 10, the reflective-transmissive element 20 can simultaneously transmit and reflect the second light beam, and the ratio of the transmitted and reflected second light beam can be adjusted according to actual needs by plating a reflective film or a transmissive film on the reflective-transmissive element 20 in a corresponding ratio. The reflective element 10 and the reflective lens element 20 together form a resonant cavity of the tunable laser 1000.
It should be noted that, in other embodiments of the present invention, the reflective element 10 and the reflective transmissive element 20 may also adopt independent optical devices, such as a reflector or a reflective transmitter made of other planar optical waveguides, or optical devices such as a mirror and a reflective transmitter are directly disposed at two opposite ends of the first planar optical waveguide 100, and as long as the scheme of satisfying the structural design is within the protection scope of the present invention, it is not described herein again.
Referring to fig. 2 and fig. 3, in the embodiment of the invention, the arrayed waveguide grating 30 can be obtained by etching or photolithography in the first planar optical waveguide 100, and the arrayed waveguide grating 30 includes an input coupler 31 and an output coupler 32A first arrayed waveguide region 33, a second arrayed waveguide region 34 and an output waveguide 35. The first array waveguide region 33 and the second array waveguide region 34 are located between the input coupler 31 and the output coupler 32, and the first array waveguide region 33 includes at least two first waveguides 331, and the second array waveguide region 34 includes at least two second waveguides 341. Two adjacent first waveguides 331 of the first waveguide array region 33 have a first optical path difference n1*ΔL1(assuming that the first arrayed waveguide region 33 is formed by arranging a first waveguide, a second waveguide and a third waveguide which are adjacent to each other in this order, if the length of the first waveguide is L, the length of the second waveguide is L- Δ L1And the third waveguide has a length of L-2 × Δ L1) Wherein n is1The group refractive index of the first beam in the first waveguide 331 is the first beam (since the first beam comprises a plurality of wavelengths, the refractive index of the first beam in the first waveguide 331 needs to be expressed by the group refractive index due to dispersion effect). Two second waveguides 341 adjacent to the second arrayed waveguide region 34 have a second optical path difference n2*ΔL2Wherein n is2Is the group refractive index, n, of the first light beam in the second waveguide1May be equal to n2And may be different. The first light beam containing a plurality of wavelengths (or a continuous wavelength) is transmitted to the input coupler 31, and the second light beam containing only one wavelength is output from the output coupler 32.
Specifically, for a conventional arrayed waveguide grating, it is assumed that the optical path difference of a plurality of waveguides included therein is n × Δ L, where n isgAnd if the group refractive index of the light beam in the waveguide is delta L, and the length difference of the two adjacent waveguides is delta L, the light beam containing a plurality of wavelengths is diffracted in the input coupler of the arrayed waveguide grating and is coupled into each waveguide. Since the output ends of the plurality of waveguides are located on the circumference of the grating circle, diffracted light generated when the light beam is diffracted in the input coupler reaches the output ends of the plurality of waveguides with the same phase. Because adjacent waveguides keep the same optical path difference ngΔ L, so that the diffracted lights of the same wavelength have the same phase difference, and the diffracted lights of different wavelengths have the same phase differenceSo that the different wavelength beams are diffracted and focused to different locations in the output coupler. For a conventional arrayed waveguide grating, the Free Spectral Range (FSR) of the transmission spectrum can be expressed by the following equation (1):
wherein λ is0Is the free space wavelength. As can be seen from equation (1), the FSR is defined by the length difference Δ L and the group index ngAnd (6) determining. The function of the arrayed waveguide grating is to demultiplex a light beam containing multiple wavelengths (or continuous wavelengths) to obtain multiple independent transmission peaks, or the arrayed waveguide grating can be equivalent to a filter, only the light beam meeting a specific diffraction condition can penetrate the arrayed waveguide grating, the penetrating wavelength is the wavelength of the obtained multiple independent transmission peaks, and other wavelengths are filtered out.
In the embodiment of the present invention, the first arrayed waveguide region 33 has a first optical path difference n1*ΔL1A second optical path difference n from the second arrayed waveguide region 342*ΔL2Are not equal, so the arrayed waveguide grating 30 can be considered as having an optical path difference of n1*ΔL1The arrayed waveguide grating has an optical path difference of n2*ΔL2Is a cascade of two conventional arrayed waveguide gratings, or is regarded as having an optical path difference of n1*ΔL1The sum of the equivalent filter sum of the arrayed waveguide grating and the optical path difference is n2*ΔL2The arrayed waveguide grating of (a) is a cascade of two equivalent filters of the equivalent filter. The first light beam passing through the arrayed waveguide grating 30 is equivalent to being filtered by two equivalent filters at the same time, so that the wavelength of the output second light beam is the transmission peak value of the transmission peak generated by the first arrayed waveguide region 33 and the transmission peak generated by the second arrayed waveguide region 34, which are coincident with each other in wavelength. Referring to FIG. 4 and FIG. 5, FIG. 4 shows an optical path difference n1*ΔL1The conventional arrayed waveguide grating has an optical path difference of n2*ΔL2The wavelength distribution of the transmission peak of the conventional arrayed waveguide grating shows that the optical path difference is n1*ΔL1Arrayed waveguide light ofThe difference between the grating and the optical path is n2*ΔL2The transmission peaks under the arrayed waveguide grating of (1) approximately coincide at a wavelength of 1.564 microns, and thus the wavelength of the second beam output by the arrayed waveguide beam 30 is 1.564 microns, as shown in fig. 5.
In the embodiment of the present invention, the arrayed waveguide grating 30 further includes a first electrode 37 and a second electrode 38, the first electrode 37 and the second electrode 38 can be fixed on the first planar optical waveguide 100 by evaporation or sputtering, and the like, the first electrode 37 is electrically connected to each first waveguide 331 in the first arrayed waveguide region 33, and the second electrode 38 is electrically connected to each second waveguide 341 in the second arrayed waveguide region 34. The first electrode 37 adjusts the refractive index of each first waveguide 331 of the first array waveguide region 33 by applying a current or a voltage, thereby adjusting the first optical path difference (group refractive index is generally a function of the refractive index of the material and is related to the wavelength distribution of the first light beam); the second electrode 38 adjusts the refractive index of each second waveguide 341 of the second arrayed waveguide region 34 by applying a current or a voltage, thereby adjusting the second optical path difference. Because the arrayed waveguide grating 30 can generate different transmission peak distributions according to different first optical path differences and second optical path differences, the coincident transmission peak values also change correspondingly, and further the wavelength of the output second light beam also changes correspondingly, so that the effect of adjusting the wavelength of the second light beam is achieved. The principles of the first and second electrodes 37 and 38 modulating the refractive indexes of the first and second waveguides 331 and 341 include, but are not limited to: the thermo-optic effect, the electro-optic effect, the effect of changing the refractive index based on the change of the concentration of the carrier, the magneto-optic effect, the piezoelectric effect or the electric absorption effect, etc. are all within the protection scope of the present invention as long as the modulation mode of the design structure provided by the embodiment of the present invention is in accordance with the present invention, and the details are not repeated herein.
It should be noted that in other embodiments of the present invention, only the first electrode 37 or only the second electrode 38 may be provided, and these designs are all within the protection scope of the present invention.
In the embodiment of the present invention, the gain medium 40 may be obtained by doping a working medium after etching or photolithography on the first planar optical waveguide 100, where the working medium may be erbium, praseodymium, or other materials that can be used as a working medium of a laser. The gain medium 40 is used for generating the first beam of light that is oscillated and simultaneously gaining the second beam of light. Specifically, an external pumping source pumps (may be optical pumping or electrical pumping) the gain medium 40, so that the gain medium 40 generates population inversion (that is, the population at a high energy level is greater than that at a low energy level), and emits the first light beam, the first light beam generates the second light beam after passing through the arrayed waveguide grating 30, the second light beam propagates back and forth in the resonant cavity, and when passing through the gain medium 40, due to a stimulated radiation effect, the gain medium 40 generates laser light whose wavelength and phase are consistent with those of the second light beam, so as to gain-amplify the second light beam, so as to compensate for various losses generated in the process of propagating the second light beam in the resonant cavity. Therefore, the second light beam can continuously and stably propagate back and forth in the resonant cavity, and when the tunable laser 1000 is in stable operation, the gain effect of the gain medium 40 is exactly equal to the loss generated when the second light beam propagates back in the resonant cavity, wherein the loss includes the loss generated when the second light beam is transmitted through the reflective element 10 and the reflective transmissive element 20, the loss generated when the second light beam is scattered, diffracted and other absorption losses in the resonant cavity.
In the embodiment of the present invention, the tunable laser 1000 further includes a phase modulator 50, and the phase modulator 50 is disposed between the arrayed waveguide grating 30 and the reflective-transmissive element 20. The phase modulator 50 may be obtained by evaporating or sputtering a metal electrode on the first planar optical waveguide 1000, and applying a current or a voltage to the metal electrode to change the refractive index of the first planar optical waveguide 100 or other material doped or formed on the phase modulator 50. The phase modulator 50 is used to maintain the output power of the second beam stable, e.g. by fine tuning to align the longitudinal mode in the laser cavity with the second beam wavelength, thereby avoiding power fluctuations.
Referring to fig. 6, it is understood that, in other embodiments of the present invention, the positions of the arrayed waveguide grating 30, the gain medium 40 and the phase modulator 50 may be disposed in various manners, such as disposing the phase modulator 50 between the arrayed waveguide grating 30 and the gain medium 40, disposing the gain medium 40 between the arrayed waveguide grating 30 and the phase modulator 50, or disposing the arrayed waveguide grating 30 between the gain medium 40 and the phase modulator 50, which is not limited in the present invention.
Referring to fig. 7, fig. 7 is a schematic diagram of a tunable laser 2000 according to a second embodiment of the present invention, where the tunable laser 2000 includes a reflective-transmissive element 220, an arrayed waveguide grating 230, a gain medium 240 and a phase modulator 250, and the manufacturing manners and functions of the reflective-transmissive element 220, the arrayed waveguide grating 230, the gain medium 240 and the phase modulator 250 are the same as those of the reflective-transmissive element 20, the arrayed waveguide grating 30, the gain medium 40 and the phase modulator 50 in the first embodiment, and are not described herein again.
The difference is that: the gain medium 240 is separately fabricated in a second planar optical waveguide 2100, and the reflective transmissive element 220, the arrayed waveguide grating 230, and the phase modulator 250 are fabricated in the first planar optical waveguide 100. The second planar optical waveguide 2100 includes a first end surface 241 and a second end surface 242 opposite to the first end surface 241, wherein the first end surface 241 may be coated with an antireflection film, and the second end surface 242 forms a reflection surface by cleaving to serve as a reflection element to reflect the second light beam. Preferably, the reflecting surface may be coated with a reflecting film in order to obtain higher reflectivity.
In the embodiment of the present invention, a lens 260 may be further disposed between the first planar optical waveguide 100 and the second planar optical waveguide 2100, and the lens 260 is used for collimating the incident light. Specifically, the second light beam transmitted by the gain medium 240 is collimated by the lens 260 and then transmitted to the arrayed waveguide grating 230, or the second light beam transmitted by the arrayed waveguide grating 230 is collimated by the lens 260 and then transmitted to the gain medium 240.
It should be noted that, in the embodiment of the present invention, the tunable laser 2000 may further include a functional unit 270, the reflective and transmissive element 220 is disposed between the functional unit 270 and the phase modulator 250, and the functional unit 270 includes, but is not limited to: a receiving unit, a modulating unit or a filtering unit to receive, modulate or filter the outputted second light beam.
It should be noted that, in the embodiment of the present invention, the relative positions of the arrayed waveguide grating 230, the gain medium 240, and the phase modulator 250 may be exchanged, for example, the phase modulator 250 may be separately disposed in the second planar optical waveguide 2100, the gain medium 240 and the arrayed waveguide grating 230 are disposed in the first planar optical waveguide 100, or the arrayed waveguide grating 230, the gain medium 240, and the phase modulator 250 are disposed in the same planar optical waveguide, and these structural design schemes are within the protection scope of the present invention, and are not described herein again.
Referring to fig. 8, fig. 8 is a schematic diagram of a tunable laser 3000 according to a third embodiment of the present invention. The tunable laser 3000 includes a reflective element 310, an arrayed waveguide grating 330, a gain medium 340, and a phase modulator 350. The gain medium 340 is fabricated on a second planar optical waveguide 3100, and the arrayed waveguide grating 330 and the phase modulator 350 are fabricated on the first planar optical waveguide 100. The second planar optical waveguide 3100 includes a first end surface 341 and a second end surface 342, wherein the first end surface 341 may be coated with an antireflection film, and the second end surface 342 is cleaved to form a smooth surface as a reflective and transmissive element, so that the second light beam is output through the second end surface 342.
It should be noted that, in the embodiment of the present invention, a lens 360 may be further disposed between the first planar optical waveguide 100 and the second planar optical waveguide 3100, and the lens 360 is used for collimating the incident light. Specifically, the second light beam transmitted by the gain medium 340 is collimated by the lens 360 and then transmitted to the arrayed waveguide grating 330, or the second light beam transmitted by the arrayed waveguide grating 330 is collimated by the lens 360 and then transmitted to the gain medium 340.
It should be noted that, in the embodiment of the present invention, the relative positions of the arrayed waveguide grating 330, the gain medium 340, and the phase modulator 350 may be changed, for example, the phase modulator 350 may be separately disposed in the second planar optical waveguide 3100, and the gain medium 340 and the arrayed waveguide grating 330 are disposed in the first planar optical waveguide 100, or the arrayed waveguide grating 330, the gain medium 340, and the phase modulator 350 are disposed in the same planar optical waveguide, and these structural design schemes are within the protection scope of the present invention, and are not described herein again.
Referring to fig. 9, fig. 9 is a schematic diagram of a tunable laser 4000 according to a fourth embodiment of the invention. The tunable laser 4000 includes a reflective element 410, a reflective transmissive element 420, an arrayed waveguide grating 430, a gain medium 440, and a phase modulator 450. Wherein the reflecting element 410 is obtained by cleaving (or plating a reflecting film after cleaving) an end face of the first planar optical waveguide 100, the arrayed waveguide grating 430 includes an input coupler 431 and a plurality of waveguides 436, one end of each waveguide 436 is coupled to the input coupler 431, and the other end is directly fabricated on the reflective element 410 (or the reflective element 410 can be implemented by integrating a waveguide type reflective structure on each waveguide 436, in which case the reflective element 410 can be formed by a waveguide type reflective structure on the waveguide 436), the first light beam is distributed to each waveguide 436 through the input coupler 431, and reaches the reflecting element 410 after being transmitted in the waveguide 436, reaches the input coupler 431 again after being reflected by the reflecting element 410, and outputs the second light beam, i.e. when the input coupler 431 functions as both an input coupler and an output coupler.
Referring to fig. 1-9, in operation, the gain medium 40 is pumped by a pump source to emit a first light beam having a plurality of wavelengths (or a continuous wavelength), and the first light beam is coupled through the input couplerThe combiner 31 diffracts to the first arrayed waveguide region 33 and the second arrayed waveguide region 34 of the arrayed waveguide grating 30, and the first waveguide 331 in the first arrayed waveguide region 33 has a first optical path difference n1*ΔL1The second waveguide 341 in the second arrayed waveguide region 34 has a second optical path difference n2*ΔL2The first arrayed waveguide region 33 outputs the first optical path difference n1*ΔL1A plurality of determined transmission peaks, the second arrayed waveguide region 34 outputs the second optical path difference n2*ΔL2A plurality of transmission peaks are determined, so that the output waveguide 35 outputs a transmission peak value with a wavelength coinciding with that of the plurality of transmission peaks output by the first array waveguide region 33 and the second array waveguide region 34, that is, the wavelength of the second light beam is the wavelength of the coinciding transmission peak. The second light beam propagates back and forth in the resonant cavity formed by the reflective element 10 and the transmissive element 20, and passes through the arrayed waveguide grating 30, the gain medium 40 and the phase modulator 50 during the propagation. When the second light beam simultaneously satisfies the amplitude condition and the phase condition in the resonant cavity, the second light beam can stably transmit in the resonant cavity and continuously output the output light. When the wavelength of the second light beam needs to be changed, the refractive indexes of the waveguides 331 of the first array waveguide region 33 and the waveguides 341 of the second array waveguide region 34 can be changed by loading the required voltage or voltage on the first electrode 37 and the second electrode 38, that is, the adjustment of the first optical path difference n is equivalent to the adjustment of the refractive index of the waveguides 341 of the first array waveguide region 33 and the refractive index of the waveguides 341 of the second array waveguide region 341*ΔL1And the second optical path difference is n2*ΔL2And further changing the wavelength distribution of the transmission peak, thereby changing the wavelength of the second light beam and realizing the effect of adjusting the wavelength of the second light beam.
It should be noted that, in the embodiments of the present invention, the devices, such as the reflective element 10, the reflective transmissive element 20, the arrayed waveguide grating 30, the gain medium 40, and the phase modulator 50, may be fabricated on the planar optical waveguide, or may be independent optical devices, or may be partially fabricated on the planar optical waveguide, and partially employ independent optical devices, which are all within the protection scope of the present invention.
In summary, in the tunable laser 1000 provided in the embodiment of the present invention, by designing a waveguide array grating 30 including two length differences, demultiplexing or filtering of the input first light beam is implemented to output a second light beam only including one wavelength, and the wavelength of the second light beam can be further adjusted by the first electrode 37 and the second electrode 38 evaporated or sputtered on the waveguide array grating 30, so as to implement an effect of continuously adjusting the wavelength. The tunable laser 1000 provided by the invention can be integrally manufactured on a planar optical waveguide 100, so that the tunable laser has the advantages of high integration level, small volume, large wavelength adjustment range, low requirements on process manufacturing and the like, and meets the use requirements of high-capacity and high-speed optical transmission and new-generation optical devices.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (11)

  1. An arrayed waveguide grating comprising an input coupler, wherein the arrayed waveguide grating further comprises a first arrayed waveguide region and a second arrayed waveguide region, the first arrayed waveguide region comprises a plurality of first waveguides, the adjacent first waveguides have a first optical path difference, the second arrayed waveguide region comprises a plurality of second waveguides, the adjacent second waveguides have a second optical path difference, and the first optical path difference is not equal to the second optical path difference.
  2. The arrayed waveguide grating of claim 1, further comprising a first electrode electrically connected to the first plurality of waveguides, the first electrode configured to apply a voltage to the first plurality of waveguides to modulate the first optical path difference.
  3. The arrayed waveguide grating of claim 1 or 2, further comprising a second electrode electrically connected to the second plurality of waveguides, the second electrode for applying a voltage to the second plurality of waveguides to modulate the second optical path difference.
  4. A tunable laser comprising a reflective element, a reflective transmissive element and a gain medium, further comprising an arrayed waveguide grating according to any one of claims 1 to 3, wherein the arrayed waveguide grating and the gain medium are disposed between the reflective element and the reflective transmissive element.
  5. The tunable laser of claim 4, wherein one end of the first waveguides and the second waveguides of the arrayed waveguide grating is disposed on the reflective element, and the other end of the first waveguides and the second waveguides are coupled to the input coupler, the first light beam is distributed to the first waveguides and the second waveguides through the input coupler, transmitted through the first waveguides and the second waveguides, and reflected by the reflective element to the input coupler, so as to generate the second light beam, and the input coupler outputs the second light beam.
  6. The tunable laser of claim 5, wherein the reflective element is comprised of a waveguide-type reflective structure integrated over the plurality of first waveguides and the plurality of second waveguides.
  7. The tunable laser of claim 4, wherein the arrayed waveguide grating further comprises an output coupler, and wherein the first and second plurality of waveguides of the arrayed waveguide grating are coupled at one end to the output coupler and at the other end to the input coupler.
  8. The tunable laser of any one of claims 4 to 7, further comprising a phase modulator disposed between the reflective element and the reflective transmissive element.
  9. The tunable laser of claim 8, wherein the phase modulator is obtained by covering a metal electrode on the first planar optical waveguide and changing the refractive index of the first planar optical waveguide by applying a current to the metal electrode; alternatively, the first and second electrodes may be,
    the phase modulator is obtained by covering the first planar optical waveguide with a metal electrode, and by applying a current to the metal electrode to change the refractive index of a predetermined phase modulating material doped and formed on the phase modulator.
  10. The tunable laser of claim 8 or 9, further comprising a second planar optical waveguide on which the gain medium and the reflective element are fabricated, wherein the arrayed waveguide grating, the phase modulator, and the reflective transmissive element are fabricated on the first planar optical waveguide; alternatively, the first and second electrodes may be,
    the gain medium and the reflection and transmission element are manufactured on the second plane optical waveguide, and the arrayed waveguide grating, the phase modulator and the reflection element are manufactured on the first plane optical waveguide.
  11. The tunable laser of claim 10, wherein a lens is disposed between the first planar optical waveguide and the second planar optical waveguide.
CN201480077957.4A 2014-09-26 2014-09-26 Array waveguide grating and tunable laser with the array waveguide grating Active CN106461874B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2014/087551 WO2016045087A1 (en) 2014-09-26 2014-09-26 Array waveguide grating and tunable laser having same

Publications (2)

Publication Number Publication Date
CN106461874A true CN106461874A (en) 2017-02-22
CN106461874B CN106461874B (en) 2019-09-27

Family

ID=55580134

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201480077957.4A Active CN106461874B (en) 2014-09-26 2014-09-26 Array waveguide grating and tunable laser with the array waveguide grating

Country Status (2)

Country Link
CN (1) CN106461874B (en)
WO (1) WO2016045087A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113284964A (en) * 2021-04-22 2021-08-20 北京邮电大学 Guided mode photoelectric detector

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2993743B1 (en) 2014-09-02 2017-05-10 Huawei Technologies Co., Ltd. Tunable laser and method for tuning a lasing mode
GB2547467A (en) * 2016-02-19 2017-08-23 Rockley Photonics Ltd Tunable laser
GB2547466B (en) 2016-02-19 2021-09-01 Rockley Photonics Ltd Discrete wavelength tunable laser
US11699892B2 (en) 2016-02-19 2023-07-11 Rockley Photonics Limited Discrete wavelength tunable laser
FR3061301B1 (en) * 2016-12-26 2020-09-04 Commissariat Energie Atomique OBJECT OBSERVATION PROCESS

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001083341A (en) * 1999-09-13 2001-03-30 Furukawa Electric Co Ltd:The Array waveguide type diffraction grating
WO2007123157A1 (en) * 2006-04-20 2007-11-01 National University Corporation Nagoya University Wavelength group optical demultiplexer, wavelength group optical multiplexer, and wavelength group light selection switch
EP1881572A1 (en) * 2006-07-18 2008-01-23 Electronics and Telecommunications Research Institute Long cavity single-mode laser diode
CN201159783Y (en) * 2008-01-07 2008-12-03 浙江大学 Polarization-insensitive array wave-guide optical grating
CN102204037A (en) * 2011-05-10 2011-09-28 华为技术有限公司 Self injection laser, wave division multiplexing passive optical network system and optical line terminal
US20130011098A1 (en) * 2011-07-06 2013-01-10 Infinera Corporation Wide passband awg
CN103091783A (en) * 2013-01-25 2013-05-08 华中科技大学 Tunable array waveguide grating based on liquid crystal waveguides

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001083341A (en) * 1999-09-13 2001-03-30 Furukawa Electric Co Ltd:The Array waveguide type diffraction grating
WO2007123157A1 (en) * 2006-04-20 2007-11-01 National University Corporation Nagoya University Wavelength group optical demultiplexer, wavelength group optical multiplexer, and wavelength group light selection switch
EP1881572A1 (en) * 2006-07-18 2008-01-23 Electronics and Telecommunications Research Institute Long cavity single-mode laser diode
CN201159783Y (en) * 2008-01-07 2008-12-03 浙江大学 Polarization-insensitive array wave-guide optical grating
CN102204037A (en) * 2011-05-10 2011-09-28 华为技术有限公司 Self injection laser, wave division multiplexing passive optical network system and optical line terminal
US20130011098A1 (en) * 2011-07-06 2013-01-10 Infinera Corporation Wide passband awg
CN103091783A (en) * 2013-01-25 2013-05-08 华中科技大学 Tunable array waveguide grating based on liquid crystal waveguides

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113284964A (en) * 2021-04-22 2021-08-20 北京邮电大学 Guided mode photoelectric detector
CN113284964B (en) * 2021-04-22 2022-06-24 北京邮电大学 Guided mode photoelectric detector

Also Published As

Publication number Publication date
WO2016045087A1 (en) 2016-03-31
CN106461874B (en) 2019-09-27

Similar Documents

Publication Publication Date Title
EP1704428B1 (en) Tunable resonant grating filters
CN106461874A (en) Array waveguide grating and tunable laser having same
US10205299B2 (en) External cavity laser comprising a photonic crystal resonator
US7062131B2 (en) Optical coupling for whispering-gallery-mode resonators via waveguide gratings
JP4299240B2 (en) Method and apparatus for tunable wavelength conversion using Bragg gratings and lasers in semiconductor substrates
US8885677B1 (en) Semiconductor external cavity laser with integrated planar waveguide bragg grating and wide-bandwidth frequency modulation
JP5474844B2 (en) Tunable resonant grating filter
CN104254950A (en) Wavelength-tunable external cavity laser diode with a GRISM for OCT
US6697411B2 (en) Modulatable multi-wavelength semiconductor external cavity laser
CN107611777A (en) The narrow linewidth semiconductor outside cavity gas laser and control method of a kind of flexible wavelength
US20040218250A1 (en) Miniaturized external cavity laser (ECL) implemented with acoustic optical tunable filter
Abreu-Afonso et al. Continuously tunable microwave photonic filter using a multiwavelength fiber laser
CN115668016A (en) Photon pair source for quantum applications
JP4907357B2 (en) Light wavelength conversion light source
Yi-Yan et al. Two-dimensional grating unit cell demultiplexer for thin-film optical waveguides
EP1043817A2 (en) Light emitting module
US6795472B2 (en) Laser with a resonant optical reflector
US20060056465A1 (en) Laser with reflective etalon tuning element
JP6497699B2 (en) Light modulation device and light modulation system
JP7385158B2 (en) Tunable laser diode
US7075955B2 (en) Integrated narrow-line tunable optical parametric oscillator
Fang et al. External Cavity Semiconductor Lasers
KR20070003801A (en) Tunable resonant grating filters
RU2095901C1 (en) Multichannel semiconductor laser
CN114583541A (en) Hybrid integrated laser

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant