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Photonic-circuit-integrated titanium:sapphire laser

Nature Photonics volume 17, pages 338–345 (2023)Cite this article

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Abstract

Compact narrow-linewidth visible lasers are pivotal components for optical sensing, metrology and communications, as well as precision atomic and molecular spectroscopy. With an emission bandwidth approaching an octave, titanium-doped sapphire (Ti:Sa) lasers are key tools for producing solid-state lasing across visible and near-infrared bands; however, today’s commercial Ti:Sa laser systems require high pump power and rely on expensive tabletop components, which restrict them to laboratory settings. In this paper we present a photonic-circuit-integrated Ti:Sa laser that combines the Ti:Sa gain medium with a silicon-nitride-on-sapphire integrated photonics platform, resulting in high portability with minimal power consumption. We demonstrate Ti:Sa lasing from 730 nm to 830 nm by tightly confining the pump and lasing modes to a single microring resonator, reducing the lasing threshold by orders of magnitude down to 6.5 mW when compared with the free-space Ti:Sa lasers. Due to the low threshold, turn-key Ti:Sa laser operation is achieved by leveraging a commercially available indium gallium nitride pump diode. Our prototype photonic-circuit-integrated Ti:Sa laser opens a reliable pathway for broadband tunable lasers in the next generation of active–passive-integrated visible photonics.

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Fig. 1: Chip-integrated Ti:Sa laser system on a SiN-on-sapphire photonic platform.
Fig. 2: Ultra-low threshold photonic circuit integrated Ti:Sa laser.
Fig. 3: Working principle of integrated Ti:Sa laser and measured results.
Fig. 4: External feedback photonic circuits for single-mode lasing and wavelength selection.
Fig. 5: Diode-pumped Ti:Sa laser.

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Data availability

The data that support the findings of this study are available at https://doi.org/10.5281/zenodo.7425191.

Code availability

All relevant computer codes supporting this study are available from the corresponding author on reasonable request.

References

  1. Moulton, P. Ti-doped sapphire: tunable solid-state laser. Optics News 8, 9 (1982).

    Article  Google Scholar 

  2. Moulton, P. F. Spectroscopic and laser characteristics of Ti:Al2O3. J. Opt. Soc. Am. B 3, 125–133 (1986).

    Article  ADS  Google Scholar 

  3. Fomichev, S., Popruzhenko, S., Zaretsky, D. & Becker, W. Laser-induced nonlinear excitation of collective electron motion in a cluster. J. Phys. B 36, 3817 (2003).

    Article  ADS  Google Scholar 

  4. Ishii, N. et al. Carrier-envelope phase-dependent high harmonic generation in the water window using few-cycle infrared pulses. Nat. Commun. 5, 1–6 (2014).

    Article  ADS  Google Scholar 

  5. Stobińska, M. et al. Quantum interference enables constant-time quantum information processing. Sci. Adv. 5, eaau9674 (2019).

    Article  ADS  Google Scholar 

  6. Popmintchev, D. et al. Ultraviolet surprise: efficient soft X-ray high-harmonic generation in multiply ionized plasmas. Science 350, 1225–1231 (2015).

    Article  ADS  MathSciNet  Google Scholar 

  7. Sótér, A. et al. High-resolution laser resonances of antiprotonic helium in superfluid 4He. Nature 603, 411–415 (2022).

    Article  ADS  Google Scholar 

  8. Ideguchi, T. et al. Coherent raman spectro-imaging with laser frequency combs. Nature 502, 355–358 (2013).

    Article  ADS  Google Scholar 

  9. Grinin, A. et al. Two-photon frequency comb spectroscopy of atomic hydrogen. Science 370, 1061–1066 (2020).

    Article  ADS  Google Scholar 

  10. Kumagai, H. et al. Ablation of polymer films by a femtosecond high-peak-power Ti:sapphire laser at 798 nm. Appl. Phys. Lett. 65, 1850–1852 (1994).

    Article  ADS  Google Scholar 

  11. Curley, P., Ferguson, A., White, J. & Amos, W. Application of a femtosecond self-sustaining mode-locked Ti:sapphire laser to the field of laser scanning confocal microscopy. Opt Quantum Electron. 24, 851–859 (1992).

    Article  Google Scholar 

  12. König, K. Multiphoton microscopy in life sciences. J. Microsc. 200, 83–104 (2000).

    Article  Google Scholar 

  13. Klein, J. & Kafka, J. D. The flexible research tool. Nat. Photon. 4, 289–289 (2010).

    Article  Google Scholar 

  14. Rapoport, W. & Khattak, C. P. Titanium sapphire laser characteristics. Appl. Opt. 27, 2677–2684 (1988).

    Article  ADS  Google Scholar 

  15. Spence, D. E., Kean, P. N. & Sibbett, W. 60-fsec Pulse generation from a self-mode-locked Ti:sapphire laser. Opt. Lett. 16, 42–44 (1991).

    Article  ADS  Google Scholar 

  16. Fortier, T. M., Bartels, A. & Diddams, S. A. Octave-spanning Ti:sapphire laser with a repetition rate >1 GHz for optical frequency measurements and comparisons. Opt. Lett. 31, 1011–1013 (2006).

    Article  ADS  Google Scholar 

  17. Bartels, A., Dekorsy, T. & Kurz, H. Femtosecond Ti:sapphire ring laser with a 2-GHz repetition rate and its application in time-resolved spectroscopy. Opt. Lett. 24, 996–998 (1999).

    Article  ADS  Google Scholar 

  18. Hall, J. L. Nobel lecture: defining and measuring optical frequencies. Rev. Mod. Phys. 78, 1279 (2006).

    Article  ADS  Google Scholar 

  19. Wall, K. F. & Sanchez, A. Titanium sapphire lasers. Linc. Lab. j. 3, 447–462 (1990).

    Google Scholar 

  20. Hickey, L. M., Apostolopoulos, V., Eason, R. W., Wilkinson, J. S. & Anderson, A. A. Diffused Ti:sapphire channel-waveguide lasers. J. Opt. Soc. Am. B 21, 1452–1462 (2004).

    Article  ADS  Google Scholar 

  21. Pollnau, M. et al. Ti:sapphire waveguide lasers. Laser Phys. Lett. 4, 560 (2007).

    Article  ADS  Google Scholar 

  22. Grivas, C. et al. Generation of multi-gigahertz trains of phase-coherent femtosecond laser pulses in Ti:sapphire waveguides. Laser Photon. Rev. 12, 1800167 (2018).

    Article  ADS  Google Scholar 

  23. Grivas, C., Corbari, C., Brambilla, G. & Lagoudakis, P. G. Tunable, continuous-wave Ti:sapphire channel waveguide lasers written by femtosecond and picosecond laser pulses. Opt. Lett. 37, 4630–4632 (2012).

    Article  ADS  Google Scholar 

  24. Wu, L. et al. Growth and laser properties of Ti:sapphire single crystal fibres. Electron. Lett. 31, 1151–1152 (1995).

    Article  ADS  Google Scholar 

  25. Yang, T.-T. et al. Widely tunable, 25-mW power, Ti:sapphire crystal-fiber laser. IEEE Photon. Technol. Lett. 31, 1921–1924 (2019).

    Article  ADS  Google Scholar 

  26. Azeem, F. et al. Ultra-low threshold titanium-doped sapphire whispering-gallery laser. Adv. Opt. Mater. 10, 2102137 (2022).

    Article  Google Scholar 

  27. Xiang, C. et al. High-performance lasers for fully integrated silicon nitride photonics. Nat. Commun. 12, 1–8 (2021).

    Article  MathSciNet  Google Scholar 

  28. Li, N. et al. Monolithically integrated erbium-doped tunable laser on a CMOS-compatible silicon photonics platform. Opt. Express 26, 16200–16211 (2018).

    Article  ADS  Google Scholar 

  29. Liu, Y. et al. A photonic integrated circuit-based erbium-doped amplifier. Science 376, 1309–1313 (2022).

    Article  ADS  Google Scholar 

  30. Harrison, J., Finch, A., Rines, D. M., Rines, G. A. & Moulton, P. F. Low-threshold, CW, all-solid-state Ti:Al2O3 laser. Opt. Lett. 16, 581–583 (1991).

    Article  ADS  Google Scholar 

  31. Wang, S.-C. et al. Laser-diode pumped glass-clad Ti:sapphire crystal fiber laser. Opt. Lett. 41, 3217–3220 (2016).

    Article  ADS  Google Scholar 

  32. Guo, X., Zou, C.-L. & Tang, H. X. Second-harmonic generation in aluminum nitride microrings with 2500%/W conversion efficiency. Optica 3, 1126–1131 (2016).

    Article  ADS  Google Scholar 

  33. Sorace-Agaskar, C. et al. Versatile silicon nitride and alumina integrated photonic platforms for the ultraviolet to short-wave infrared. IEEE J. Sel. Top. Quantum Electron. 25, 1–15 (2019).

    Article  Google Scholar 

  34. Harder, C., Vahala, K. & Yariv, A. Measurement of the linewidth enhancement factor α of semiconductor lasers. Appl. Phys. Lett. 42, 328–330 (1983).

    Article  ADS  Google Scholar 

  35. Stéphan, G., Tam, T., Blin, S., Besnard, P. & Têtu, M. Laser line shape and spectral density of frequency noise. Phys. Rev. A 71, 043809 (2005).

    Article  ADS  Google Scholar 

  36. Hulme, J., Doylend, J. & Bowers, J. Widely tunable Vernier ring laser on hybrid silicon. Opt. Express 21, 19718–19722 (2013).

    Article  ADS  Google Scholar 

  37. Gorodetsky, M. L., Pryamikov, A. D. & Ilchenko, V. S. Rayleigh scattering in high-Q microspheres. J. Opt. Soc. Am. B 17, 1051–1057 (2000).

    Article  ADS  Google Scholar 

  38. Belt, M. & Blumenthal, D. J. Erbium-doped waveguide DBR and DFB laser arrays integrated within an ultra-low-loss Si3N4 platform. Opt. Express 22, 10655–10660 (2014).

    Article  ADS  Google Scholar 

  39. Shen, B. et al. Integrated turnkey soliton microcombs. Nature 582, 365–369 (2020).

    Article  ADS  Google Scholar 

  40. Xiang, C. et al. Laser soliton microcombs heterogeneously integrated on silicon. Science 373, 99–103 (2021).

    Article  ADS  Google Scholar 

  41. Shtyrkova, K. et al. Integrated CMOS-compatible Q-switched mode-locked lasers at 1900 nm with an on-chip artificial saturable absorber. Opt. Express 27, 3542–3556 (2019).

    Article  ADS  Google Scholar 

  42. Desiatov, B., Shams-Ansari, A., Zhang, M., Wang, C. & Lončar, M. Ultra-low-loss integrated visible photonics using thin-film lithium niobate. Optica 6, 380–384 (2019).

    Article  ADS  Google Scholar 

  43. Liu, X. et al. Ultra-high-Q UV microring resonators based on a single-crystalline AlN platform. Optica 5, 1279–1282 (2018).

    Article  ADS  Google Scholar 

  44. Jung, H. et al. Tantala kerr nonlinear integrated photonics. Optica 8, 811–817 (2021).

    Article  ADS  Google Scholar 

  45. Sawada, R., Tanaka, H., Sugiyama, N. & Kannari, F. Wavelength-multiplexed pumping with 478-and 520-nm indium gallium nitride laser diodes for Ti:sapphire laser. Appl. Opt. 56, 1654–1661 (2017).

    Article  ADS  Google Scholar 

  46. Roth, P. W., Maclean, A. J., Burns, D. & Kemp, A. J. Directly diode-laser-pumped Ti:sapphire laser. Opt. Lett. 34, 3334–3336 (2009).

    Article  ADS  Google Scholar 

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Acknowledgements

This work is supported by DARPA LUMOS under contract no. HR0011-20-2-0045. We thank X. Liu, A. Bruch, Z. Gong, J. Surya, J. Lu, F. Yang, C. Mi, J. Han and G. Keeler for fruitful discussions. We thank Y. Sun, S. Reinhart, K. Woods and M. Rooks for assistance with device fabrication. We thank J.-h. Kang, R. Elafandy and R. Cheng for their help in material characterization.

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Authors and Affiliations

  1. Department of Electrical Engineering, Yale University, New Haven, CT, USA

    Yubo Wang, Jorge A. Holguín-Lerma, Mattia Vezzoli, Yu Guo & Hong X. Tang

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  1. Yubo Wang
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  2. Jorge A. Holguín-Lerma
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  3. Mattia Vezzoli
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  4. Yu Guo
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  5. Hong X. Tang
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Contributions

H.X.T. and Y.W. conceived the experiment. Y.W. fabricated the device. Y.W. and J.A.H.-L., performed the experiment. Y.W. and J.A.H.-L. analysed the data. M.V. and Y.G. helped with the project. Y.W. and J.A.H.-L. wrote the manuscript, and all authors contributed to the manuscript. H.X.T. supervised the work.

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Correspondence to Hong X. Tang.

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Nature Photonics thanks Arnan Mitchell, Huiyun Liu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Extended data

Extended Data Fig. 1 Device fabrication.

a. Process flow of the optimized photonic circuit integrated Ti:Sa laser process, including LPCVD SiN deposition, waveguide etch, Ti:Sa crystal bonding and SiON cladding deposition. b. Optical image of a fabricated device depicting the photonic waveguides.

Extended Data Fig. 2 Lasing linewidth measurement.

a. Schematics of the optical set-up for photonic circuit integrated Ti:Sa laser. Heterodyne beatnote measurement using commercial Ti:Sa laser (M2laser) allows measurement of laser linewidth using a fast photodetector (PD) and electrical signal analyser (ESA). b. Heterodyne beating signal between the on-chip Ti:Sa laser and the reference laser with a full-wave half maximum of 120 kHz.

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Wang, Y., Holguín-Lerma, J.A., Vezzoli, M. et al. Photonic-circuit-integrated titanium:sapphire laser. Nat. Photon. 17, 338–345 (2023). https://doi.org/10.1038/s41566-022-01144-2

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