This joint issue of Optics Express and Optical Materials Express features 18 state-of-the art articles that witness actual developments in nonlinear optics, including those by authors who participated in the international conference Nonlinear Optics held in Waikoloa, Hawaii from July 15 to 19, 2019. As an introduction, the editors provide a summary of these articles that cover all aspects of nonlinear optics, from basic nonlinear effects and novel frequency windows to innovative nonlinear materials and devices, thereby paving the way for new nonlinear optical concepts and forthcoming applications.
© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Nonlinear Optics (NLO) has a long tradition as an international conference within the OSA conference series since 1990, typically held biannually at a location in Hawaii. The 2019 OSA NLO conference was held in Waikoloa on the Big Island from July 15 to 19th, is the 15th conference in this successful series.
Since nonlinear optical phenomena play a key role in many actual applications of photonics, the conference covers basic nonlinear optical phenomena as well as many applications, ranging over a wide range of energies and powers, from single-photons to zettawatts, and over broad spectral ranges, from THz to Gamma-ray frequencies. New advances arising in disruptive fields ranging from quantum nonlinear optics, over plasmonics and metamaterials up to high-field lasers and ultrafast optics applications, while new emerging applications are showing cross-fertilization with fields like machine learning, medical cell and brain science, or quantum and nanoscience.
Such, the purpose of the NLO conference is to provide continuously an international forum for discussion of all these aspects of nonlinear optics, including new physics, advanced materials, novel device concepts, as well as their applications in various news fields of science and technology.
This typically results in meetings with around 150 active participations. In 2019, it included a total of 175 oral and poster presentations from over 20 countries worldwide, including inspiring plenary talks, visionary invited talks, and a large number of contributed talks and poster presentations that gave ample opportunities for scientific interactions and discussions.
Though being only a small fraction of the many highest-level contributions, in nevertheless gives an excellent flavor of the cutting-edge topics covered by the meeting. Unlike typical conference proceedings, this feature issue has only accepted papers that report new, previously unpublished work, and we follow the regular review process for the journals with its clear criteria of scientific value and impact being independent of the conference review.
We hope readers will enjoy this issue with the resulting 19 top-level articles that highlight the state of the art in the field. We are thankful to all of the authors and reviewers for their contribution and commitment to the field. We also would like to thank Carmelita Washington from the OSA staff for their outstanding support for making this feature issue in all its steps a success.
The topical issue follows the categories that are typically falling into three categories:
- 1. Fundamental Studies and New Concepts including topics from nonlinear light propagation and quantum nonlinear optics to ultrafast phenomena,
- 2. Nonlinear Materials including fields as cold atoms, dielectric, semiconductor, metallic and polymer material as well as nanostructured and integrated systems, and
- 3. Applications, covering such diverse path breaking fields as data storage, quantum information processing, artificial intelligence, or biomedical nonlinear optical devices.
A related central theme of NLO is ultrafast nonlinear optical phenomena that are also heading for applications as ultrafast nonlinear refraction measurements [6,7], few cycle pulses in integrated nonlinear photonic circuits , or ultrashort pulses in epsilon-near-zero metamaterials at the telecom wavelength .
The advent of nanoscaled and structured materials paves the way to tomorrows’ applications of nonlinear optics, as thin film semiconductor nonlinear platforms , integrated parametric oscillators included into two-dimensional materials , or nonlinear optical circuits based on complex light two-photon absorption for inspection in microelectronics . In turn, nonlinear optical effects itself as e.g. z-scan can be developed into tools that allow characterizing optically relevant parameters of solutions and dyes .
With increasing application relevance, questions of bandwidth, phase-sensitivity, and fluctuations gain more importance. Thus, control of bistable signals  in resonators, bandwidth in optical networks , phase modulation in interconnection and network transmission , fluctuations in fiber lasers , or self-phase modulation in two-dimensional materials  are all based on nonlinear optical light matter interaction, especially third order wave mixing effects.
With the upcoming 60th birthday of the laser in 2020, the field of Nonlinear Optics is entering its 7th decade of innovations in optics and photonics. Nonlinear optics is not only as vibrant and stimulating as ever before, but is becoming more and more groundbreaking, being a trendsetter that fosters applications of disruptive technologies as quantum technologies, machine learning, or brain science within optics and photonics.
Thus, we can be curiously looking forward to the next OSA Nonlinear Optics conference that surely will continue this exiting trend, to be held in 2021 again in Waikoloa, Hawaii, USA.
1. R. Zhou, X. Liu, D. Yu, Q. Li, and H. Y. Fu, “Versatile multi-soliton patterns of noise-like pulses in a passively mode-locked fiber laser,” Opt. Express 28(2), 912–923 (2020). [CrossRef]
2. T. Mayteevarunyoo, B. A. Malomed, and D. V. Skryabin, “Spatiotemporal dissipative solitons and vortices in a multi-transverse-mode fiber laser,” Opt. Express 27(26), 37364–37373 (2019). [CrossRef]
3. L.-R. Robichaud, S. Duval, L.-P. Pleau, V. Fortin, S. T. Bah, S. Châtigny, R. Vallée, and M. Bernier, “High-power supercontinuum generation in the mid-infrared pumped by a soliton self-frequency shifted source,” Opt. Express 28(1), 107–115 (2020). [CrossRef]
4. A. Rampur, Y. Stepanenko, G. Stępniewski, T. Kardaś, D. Dobrakowski, D.-M. Spangenberg, T. Feurer, A. Heidt, and M. Klimczak, “Ultra low-noise coherent supercontinuum amplification and compression below 100 fs in an all-fiber polarization-maintaining thulium fiber amplifier,” Opt. Express 27(24), 35041–35051 (2019). [CrossRef]
5. Y. Liu, S. L. Liang, G. R. Jin, and Y. B. Yu, “Genuine tripartite Einstein-Podolsky-Rosen steering in the cascaded nonlinear processes of third-harmonic generation,” Opt. Express 28(3), 2722–2731 (2020). [CrossRef]
6. T. R. Ensley and N. K. Bambha, “Ultrafast nonlinear refraction measurements of infrared transmitting materials in the mid-wave infrared,” Opt. Express 27(26), 37940–37951 (2019). [CrossRef]
7. S. L. Walden, J. F. S. Fernando, M. P. Shortell, and E. A. Jaatinen, “Accurate determination of nonlinear refraction in ZnO and Au composite nanostructures,” Opt. Mater. Express 10(2), 653–661 (2020). [CrossRef]
8. D. R. Carlson, P. Hutchison, D. D. Hickstein, and S. B. Papp, “Generating few-cycle pulses with integrated nonlinear photonics,” Opt. Express 27(26), 37374–37382 (2019). [CrossRef]
9. J. Wu, B. A. Malomed, H. Y. Fu, and Q. Li, “Self-interaction of ultrashort pulses in an epsilon-near-zero nonlinear material at the telecom wavelength,” Opt. Express 27(26), 37298–37307 (2019). [CrossRef]
10. J. H. Sierra, R. C. Rangel, R. E. Samad, N. D. Vieira, M. I. Alayo, and D. O. Carvalho, “Low-loss pedestal Ta2O5 nonlinear optical waveguides,” Opt. Express 27(26), 37516–37521 (2019). [CrossRef]
11. J. Wang, J. Pang, S. Liu, H. Zhang, W. Tang, and W. Xia, “Experimental and dynamical study of a dual Q-switched intracavity OPO based on few-layer MoSe2 SA,” Opt. Express 27(25), 36474–36486 (2019). [CrossRef]
12. J. M. Hales, A. Khachatrian, J. Warner, S. Buchner, A. Ildefonso, G. N. Tzintzarov, D. Nergui, D. M. Monahan, S. D. LaLumondiere, J. D. Cressler, and D. McMorrow, “Using Bessel beams and two-photon absorption to predict radiation effects in microelectronics,” Opt. Express 27(26), 37652–37666 (2019). [CrossRef]
13. M. S. Melhado, T. G. B. de Souza, S. C. Zilio, E. C. Barbano, and L. Misoguti, “Discrimination between two distinct nonlinear effects by polarization-resolved Z-scan measurements,” Opt. Express 28(3), 3352–3360 (2020). [CrossRef]
14. S.-A. Al Graiti and S. D. Maywar, “Downstream hysteresis-shape control of a bistable optical signal created by an upstream nonlinear photonic resonator,” Opt. Express 27(26), 38404–38412 (2020). [CrossRef]
15. Y. Kaihori, Y. Yamasaki, and T. Konishi, “Bandwidth adjustment and spectral defragmentation for optical networking unit using four wave mixing spectral compression,” Opt. Express 28(2), 959–969 (2020). [CrossRef]
16. J. Cui, Y. Ji, G.-W. Lu, H. Wang, and M. Zhang, “Phase-sensitive amplifier-based optical conversion for direct detection of complex modulation format to bridge long-haul transmissions and short-reach interconnects,” Opt. Express 28(2), 2349–2365 (2020). [CrossRef]
17. A. Tehranchi and R. Kashyap, “Theoretical investigations of power fluctuations statistics in Brillouin erbium-doped fiber lasers,” Opt. Express 27(26), 37508–37515 (2019). [CrossRef]
18. T. Neupane, B. Tabibi, and F. J. Seo, “Spatial self-phase modulation in WS2 and MoS2 atomic layer,” Opt. Mater. Express 10, in press (2020).