Semiconductor laser device, diffraction grating structure, and diffraction grating
Gespeichert in:
| Titel: | Semiconductor laser device, diffraction grating structure, and diffraction grating |
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| Patent Number: | 10923,880 |
| Publikationsdatum: | February 16, 2021 |
| Appl. No: | 16/058356 |
| Application Filed: | August 08, 2018 |
| Abstract: | A semiconductor laser device is a vernier-type wavelength-tunable semiconductor laser device including an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods. At least one of the first and second reflective elements has a sampled grating structure having a reflection comb spectrum in which reflection phases at the respective reflection peaks are aligned and the intensity of a reflection peak outside a set laser emission wavelength bandwidth is lower than the intensity of a reflection peak within the laser emission wavelength bandwidth. |
| Inventors: | FURUKAWA ELECTRIC CO., LTD. (Tokyo, JP) |
| Assignees: | FURUKAWA ELECTRIC CO., LTD. (Tokyo, JP) |
| Claim: | 1. A vernier-type wavelength-tunable semiconductor laser device comprising an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods, wherein at least one of the first and second reflective elements has a sampled grating structure having a reflection comb spectrum in which reflection phases at the respective reflection peaks are aligned and an intensity of a reflection peak outside a set laser emission wavelength bandwidth is lower than an intensity of a reflection peak within the laser emission wavelength bandwidth, wherein a plurality of reflection peaks adjacent to each other within the set laser emission wavelength bandwidth have substantially the same magnitude and at least two reflection peaks outside the set laser emission wavelength bandwidth at the two ends therein have magnitude less than said same magnitude, and reflection phases substantially coincide with each other at all the reflection peaks in the reflection comb spectra without providing a phase adjustment region to perform phase adjustment in the vernier-type wavelength-tunable semiconductor laser device. |
| Claim: | 2. The vernier-type wavelength-tunable semiconductor laser device according to claim 1 , wherein at least one of the first and second reflective elements has a light-emitting region. |
| Claim: | 3. A vernier-type wavelength-tunable semiconductor laser device comprising an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods, wherein at least one of the first and second reflective elements is a diffraction grating having a sampled grating structure including a plurality of diffraction grating structures, each of the diffraction grating structures having a structure that is substantially centrosymmetric in a light progressing direction, and has the sampled grating structure having a reflection comb spectrum in which an intensity of a reflection peak outside a set laser emission wavelength bandwidth is lower than an intensity of a reflection peak within the laser emission wavelength bandwidth, wherein a plurality of reflection peaks adjacent to each other within the set laser emission wavelength bandwidth have substantially the same magnitude and at least two reflection peaks outside the set laser emission wavelength bandwidth at the two ends therein have magnitude less than said same magnitude, and reflection phases substantially coincide with each other at all the reflection peaks in the reflection comb spectra without providing a phase adjustment region to perform phase adjustment in the vernier-type wavelength-tunable semiconductor laser device. |
| Claim: | 4. The vernier-type wavelength-tunable semiconductor laser device according to claim 3 , wherein at least one of the first and second reflective elements has a light-emitting region. |
| Claim: | 5. A vernier-type wavelength-tunable semiconductor laser device comprising an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods, wherein at least one of the first and second reflective elements is a diffraction grating of a sampled grating structure including a plurality of diffraction grating structures, a plurality of sets of a high-refractive-index portion and a low-refractive-index portion having a lower refractive index than the high-refractive-index portion are alternately arranged in a predetermined direction in the diffraction grating structure, wherein the sampled grating of at least the first and second reflective elements includes regions, which include respective segments, each of the segments being formed of a diffraction grating and a waveguide region, which is connected to the diffraction grating, arranged in an optical waveguide direction, and is continuously present in only the diffraction grating of each of the segments, when a structure in which a plurality of sets of the high-refractive-index portion and the low-refractive-index portion are arranged in an alternately periodic manner is set as a basic structure, the diffraction grating structure has a structure formed by omitting at least one of the high-refractive-index portions from the basic structure, omitting at least one of the low-refractive-index portions, omitting at least one boundary between the high-refractive-index portion and the low-refractive-index portion, or performing a combination thereof, and the diffraction grating structure has a structure including a plurality of portions with alternating arrangement of the high-refractive-index portion and the low-refractive-index portion phase shifted by a ½ period from the basic structure, wherein a plurality of reflection peaks adjacent to each other within a set laser emission wavelength bandwidth have substantially the same magnitude and at least two reflection peaks outside the set laser emission wavelength bandwidth at the two ends therein have magnitude less than said same magnitude, and reflection phases substantially coincide with each other at all the reflection peaks in the reflection comb spectra without providing a phase adjustment region to perform phase adjustment in the vernier-type wavelength-tunable semiconductor laser device. |
| Claim: | 6. The vernier-type wavelength-tunable semiconductor laser device according to claim 5 , wherein at least one of the first and second reflective elements has a light-emitting region. |
| Claim: | 7. The vernier-type wavelength-tunable semiconductor laser device according to claim 5 , wherein the diffraction grating structure has a structure approximately providing a shape obtained by Fourier formation of a desired reflectivity spectrum. |
| Claim: | 8. The vernier-type wavelength-tunable semiconductor laser device according to claim 5 , wherein the diffraction grating structure has a structure approximately providing a sinc function shape obtained by Fourier formation of a rectangular window function. |
| Claim: | 9. The vernier-type wavelength-tunable semiconductor laser device according to claim 8 , wherein the diffraction grating structure has a structure that is substantially centrosymmetric in the predetermined direction. |
| Claim: | 10. The vernier-type wavelength-tunable semiconductor laser device according to claim 1 , wherein the sampled grating structure includes a plurality of diffraction grating structures, and in the diffraction grating structures a refractive index profile inside sinc function is made substantially centrosymmetric. |
| Claim: | 11. The vernier-type wavelength-tunable semiconductor laser device according to claim 3 , wherein in the diffraction grating structures a refractive index profile inside sinc function is made substantially centrosymmetric. |
| Claim: | 12. The vernier-type wavelength-tunable semiconductor laser device according to claim 5 , wherein in the diffraction grating structures a refractive index profile inside sinc function is made substantially centrosymmetric. |
| Patent References Cited: | 6141370 October 2000 Avrutsky et al. 6937638 August 2005 Fish et al. 7643532 January 2010 Fish et al. 7894693 February 2011 Fujii 8009947 August 2011 Fujii 2003/0091300 May 2003 Irino et al. 2004/0042516 March 2004 Takaki et al. 2004/0264514 December 2004 Kim 2010/0272133 October 2010 Kato 2010/0296539 November 2010 Fukuda et al. 5-333223 December 1993 2003-152274 May 2003 2004-128372 April 2004 4283869 June 2009 2010-258297 November 2010 2011-003886 January 2011 5692330 April 2015 2015-106664 June 2015 |
| Other References: | International Search Report dated Apr. 4, 2017 in PCT/JP2017/005166, filed on Feb. 13, 2017 (with English Translation). cited by applicant Written Opinion dated Apr. 4, 2017 in PCT/JP2017/005166, filed on Feb. 13, 2017. cited by applicant Ishikawa, T. et al. “Narrow Spectral Linewidth Full-Band Wavelength Tunable Lasers for Digital Coherent Communication Systems,” 2013, pp. 10 (with English Translation). cited by applicant Avrutsky, I. et al. “Design of Widely Tunable Semiconductor Lasers and the Concept of Binary Superimposed Gratings (BSG's),” IEEE Journal of Quantum Electronics, vol. 34, No. 4, 1998, pp. 13. cited by applicant Ibsen, M. et al. “Sinc-Sampled Fiber Bragg Gratings for Identical Multiple Wavelength Operation,” IEEE Photonics Technology Letters, vol. 10, No. 6, 1998, pp. 3. cited by applicant Ohki, Y. et al. “Pump Laser Module for Co-propagating Raman Amplifier,” Furukawa Review No. 24, 2003, pp. 13 (with English Translation). cited by applicant Office Action dated Nov. 4, 2020 in Japanese Application No. 2017-567025, along with an English translation. cited by applicant “Multi-wavelength laser array structure using sampled grating structure”, along with an English translation (2015). cited by applicant Office Action dated Sep. 9, 2020 in Chinese Application No. 201780010513.2, along with an English translation. cited by applicant “A New Sampled Grating Multi-Wavelength Laser Array”, along with an English translation (2015). cited by applicant |
| Primary Examiner: | Niu, Xinning(Tom) |
| Attorney, Agent or Firm: | Oblon, McClelland, Maier & Neustadt, L.L.P. |
| Dokumentencode: | edspgr.10923880 |
| Datenbank: | USPTO Patent Grants |
| Abstract: | A semiconductor laser device is a vernier-type wavelength-tunable semiconductor laser device including an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods. At least one of the first and second reflective elements has a sampled grating structure having a reflection comb spectrum in which reflection phases at the respective reflection peaks are aligned and the intensity of a reflection peak outside a set laser emission wavelength bandwidth is lower than the intensity of a reflection peak within the laser emission wavelength bandwidth. |
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