It is now 23 years since the first Topical Meeting “Nonlinear Guided Wave Phenomena” (Houston, TX, February 2-4, 1989) has been organised by George Stegeman and Roger Stolen with support of the Optical Society of America. These series of the OSA conferences known as NLGW, continued under the name “Nonlinear Photonics” starting from 2007. The latest one, in Colorado Springs in June 17-21, 2012 has been a great success despite the fierce fires advancing around the city at the time of the conference. This Focus issue is a collection of several papers presented at the conference with extended content submitted to Optics Express. Although this collection is small in comparison to the total number of papers presented at the conference, it gives a flavor of the topics considered at the meeting. It is also worthy to mention here that the next meeting “Nonlinear Photonics” is planned to be held in Barcelona - one of the main European centers on this subject.
©2012 Optical Society of America
Nonlinear photonics is a subject that includes several well developed areas of research. Among them, we can mention optoelectronics, nonlinear fiber optics, laser physics, quantum optics, photonics devices and multiplicity of applications. The most recent OSA meeting “Nonlinear Photonics” has been successfully co-located with meetings “Access Networks and In-house Communications”, “Bragg gratings, Photosensitivity and Poling in Glass Waveguides,” “Integrated Photonics Research, Silicon and Nano-Photonics,” “Signal Processing in Photonic Communications” and “Specialty Optical Fibers” under the common name “Advanced Photonics” . The meeting has been the place for presentation of the most recent innovative approaches in nonlinear optics and photonics as well as the place for efficient interaction with the leading companies in the field of photonics. A special Optoelectronics Industry Development Association (OIDA) lunch gave everyone the chance for an informal communication with industry representatives.
Another reason for strong and lasting interest in the field is that several Nobel prizes have been awarded to scientists working in it. In order to reflect this important role of photonics the two Nobel Prize winners - one of the inventors of optical maser - Prof. Charles Towns and one of the inventors of the optical frequency combs - Prof. Theodor Hänsch gave exciting public lectures at the previous meeting in Karlsruhe in 2010 that attracted significant audience.
This year’s meeting in Colorado Springs has not been an exception. Despite the known and alarming attack of disastrous bush fires around the town, the conference was a great success in terms of the number of participants and variety of the subjects covered by the conference. Just like the well-known tourist attraction near Colorado Springs - Pikes Peak gives its visitors inspiration and the feeling of Great America, the conference gave its participants the sweeping overview on the subject of Nonlinear Photonics.
To start with, let us just list the topics of the conference in the same order as in the Proceedings of the conference:
- • Temporal and spatio-temporal effects.
- • Nonlinear devices and systems
- • Spatial effects, poling, periodic structures
- • Novel nonlinear materials
- • Instabilities in nonlinear optics
- • Nonlinearities in novel propagation environments
- • Nonlinearities in lasers and dissipative systems
- • Modeling, analysis and computational techniques in nonlinear photonics
The set of topics expands from year to year to reflect the most recent advances in the field. Naturally, subjects of today’s conference significantly differ from the program 23 years ago. Those participants who had a luck to be at the first meeting in 1989 in Houston may remember most of the meetings. Until the event of 2005 in Dresden, the meeting has been known as “Nonlinear Guided Waves” (NLGW) but later was renamed to “Nonlinear Photonics” (NP). Let us list them all for the history of the conference together with the name of the meeting:
- 1. Nonlinear guided-wave phenomena: physics & applications, February 2–4, 1989, Houston, Texas, USA.
- 2. Nonlinear guided wave phenomena, September 2–4, 1991, Cambridge, England, UK.
- 3. Nonlinear guided wave phenomena, September 20–22, 1993, Cambridge, England, UK.
- 4. Nonlinear guided waves & their applications, February 23–25, 1995, Dana Point, California.
- 5. Nonlinear guided waves & their applications, August 30–September 1, 1996, Cambridge, England, UK.
- 6. Nonlinear guided waves & their applications, April 1–3, 1998, Victoria, British Columbia, Canada.
- 7. Nonlinear guided waves & their applications, September 1–3, 1999, Dijon, France
- 8. Nonlinear guided waves & their applications, March 25–28, 2001, Clearwater, Florida, USA
- 9. Nonlinear guided waves & their applications, September 1–4, 2002, Stresa, Italy.
- 10. Nonlinear guided waves & their applications, March 28–31, 2004, Toronto, Canada
- 11. Nonlinear guided waves & their applications, September 6–9, 2005, Dresden, Germany.
- 12. Nonlinear Photonics, September 2–6, 2007, Quebec City, Quebec, Canada.
- 13. Nonlinear Photonics, June 21–24, 2010, Karlsruhe, Germany.
- 14. Nonlinear Photonics, June 17–21, 2012, Colorado Springs, USA.
The average time interval between the conferences was 18 month except for a few cases when the meeting was delayed for technical reasons.
The present Focus Issue contains contributions by the authors who have been enthusiastic enough to prepare a longer paper by the deadline of submission set by the Optics Express.
Below, we provide a short introduction for each paper and classify them into several categories.
- Signal processing in (2) materials. Signal processing in (2) media is presented by D. Shayovitz and coworkers in . Using sum frequency generation (SFG) in a periodically poled lithium niobate (PPLN) crystal, the authors demonstrated a high resolution, background-free time-to-space conversion of the signal. The technique suggested by the authors may find applications in optical communications, in investigating femtosecond time scale molecular dynamics and for single wavelength channel real-time photonic analog-to-digital conversion.
- Multicasting of a single channel onto multiple channels has previously been reported in optical fibers. M. Ahlawat and coworkers in  use a (2) process to demonstrate multicasting in a novel multiple quasi-phase-matched (QPM) wavelength converter of periodically poled LiNbO3. Broadcasting of one signal into three idlers based on cascaded second harmonic generation has been achieved. Channel selective multiple broadcasting achieved in this work proves its crucial function in signal path routing and enable effective use of WDM bandwidth as well as flexible network construction.
- Signal processing in (3) bulk materials. Nonlinear signal processing in (3) or Kerr materials is presented by N. Gutman and coworkers in the paper . The authors predict a tunable all-optical switching response, with an ultra-low switching threshold in a nonlinear waveguide that supports frozen light. Slow light is achieved in terms of modes with low or even zero group velocity. The authors have also shown that in the frozen light regime the bistability and hysteresis can be avoided. The estimates indicate that such switching can be realized in silica fibers and nanowire waveguides.
- In  M. Heinrich and coworkers proposed photonic lattices with segmentation-based linear self-imaging as integrated optical limiters. The authors have demonstrated that the nonlinear delocalization leads to a continuous decrease of the overall transmission when the input powers increase. The experiment is done in a waveguide lattice created in bulk fused silica using the femtosecond laser writing technique. Such a device can be implemented in a one-dimensional setting using conventional surface-bound fabrication techniques.
- G. Huang and coworkers demonstrate in  all optical conversion of a non-return-to-zero on-off-keying (NRZ-OOK) modulation format to a RZ-16QAMmodulation format using an optical fiber in a nonlinear loop mirror. The experiment performed at 10 Gb/s is based on the use of the nonlinear loop mirror (NOLM) and a 1:2 coupler configuration. The simulation and experimental results performed in the work confirm the feasibility of this proposed converter despite the generated 16 quadrature amplitude modulation (16QAM) signals are affected in its phase by the amplitude-to-phase-noise conversion due to the amplitude dependence of cross-phase modulation (XPM) effect.
- Spatial solitons in nonlinear materials. Spatial solitons are one of the traditional subjects of the NLGWand NP meetings. Using parametric interaction in a Kerr medium, in analogy with optical pulse delay related to the slow light propagation in Kerr-type nonlinear media G. Fanjoux and coworkers  demonstrated theoretically the effect of beam steering and spatial walk-off compensation in noncollinear optical parametric amplification. The authors identified this effect as a result of the quadratic phase shift induced by parametric amplification that leads to the cancelation of the spatial walk-off and collinear propagation of all beams. Soliton array steering in a Kerr slab waveguide has been used for the experimental confirmation of this effect.
- In the work of D. Ramírez Martínez and coworkers , the waveguide properties of the asymmetric collision between the two bright spatial solitons in a nonlinear Kerr medium have been analyzed numerically. These results show that the energy carried by a probe beam guided by one soliton can be transferred after the collision to the waveguide created by the other soliton. The transmission ratio depends on the initial separation between the solitons and the angle of collision. The results can be used for design of X-junctions based on solitons.
- Four-wave mixing in waveguides and fibers. Within the last decade significant attention has been given to the processes of four-wave mixing in waveguides and optical fibers. In this issue, A. S. Solntsev with co-workers  presented the study of photon-pair generation in arrays of nonlinear waveguides through spontaneous four-wave mixing. They have shown that waveguide arrays with cubic nonlinearity can be employed as a flexible platform for all-optical manipulation of the generated bi-photon quantum statistics. These results may open new opportunities for integrated quantum photonics with all-optical controls.
- K. Krupa and coworkers  studied, experimentally, Bragg-scattering four-wave mixing in a highly nonlinear fiber at telecom wavelengths using photon counters. The authors explored the polarization dependence of this process with a continuous wave signal in the macroscopic and attenuated regime, with a wavelength shift of 23 nm. The measurements of mean photon numbers per second under various pump polarization configurations agreed well with the theoretical and numerical predictions based on classical models. The impact of noise under these different polarization configurations is discussed in detail.
- Nonlinear photonics in optical fibers. Fundamental issues as well applications such as phase sensitive, phase insensitive amplifiers, multicasting, and wavelength conversion are of great interest in modern photonics. These topics have been also reflected at the Nonlinear Photonics meeting and consequently in this special issue of Optics Express.
- An analytical theory of fiber-optic Raman polarizers was presented by V. V. Kozlov et al. in . The authors considered the Raman polarizer which is simultaneously a Raman amplifier. The device not only amplifies but also re-polarizes light. Namely, the authors propose a relatively simple and analytically tractable model – the ideal Raman polarizer, for describing the operation of this device. The model efficiently determines key device parameters such as the degree of polarization, the alignment parameter, the gain and the relative intensity noise (RIN) variance.
- J. Nuño and coworkers in  studied, numerically, relative intensity-noise (RIN) transfer from a noisy pump to the generated Stokes component in random distributed feedback (RDF) ultra-long straight line cavity Raman fiber lasers (RFL). Their results show that transfer levels are comparable to those in distributed Raman amplification and cavity based ultra-long Raman fiber lasers. The main conclusion is the behavior of RIN transfer in RDF-RFL should not prevent their use in communication schemes. The configurations that minimize RIN transfer should be chosen over noisier ones.
- The authors of  consider the effects of nonlinear phase modulation on frequency conversion by four-wave mixing (Bragg scattering) in the low-conversion regime. They derived the Green functions for this process in which the four fields interact either at the beginning or at the end of the fiber, or at the midpoint of the fiber. The authors have found that even in the presence of nonlinear phase modulation, frequency conversion with arbitrary pulse reshaping is possible.
- Fiber optical parametric amplifiers. L. Jin and coworkers  theoretically and numerically explain the power saturation and the additional phase noise brought by the fiber optical parametric amplifier (FOPA). The authors present an equation for calculating the approximate saturated signal output power. They propose the scheme for alleviating the phase noise brought by the FOPA at the saturated state and study, numerically, the amplitude noise and additional phase noise reduction of quadrature phase shift keying (QPSK) based on the saturated FOPA. The signal regenerator considered in this work can provide a promising performance when dealing with phase shift keying signals.
- Theoretical studies of pulse generation in fiber optic parametric amplifiers (FOPAs) with the intensity modulated pump have shown that the pulse shape is influenced by the signal detuning from the pump wavelength. In , A. A. Vedadi and coworkers verify experimentally the pulse shape dependence on the wavelength detuning between the pump and signal, and discuss the impact by other parameters such as noise, pump saturation and walk-off. Generated pulses take a near Sinc shape which may have potential applications for all-optical Nyquist limited transmitters and receivers.
- Using phase sensitive parametric amplification in a highly nonlinear lead-silicate optical fiber, M. A. Ettabib and coworkers experimentally demonstrated regeneration of a 40- Gb/s differential phase shift keying (DPSK) signal in a 1.7-m long highly nonlinear lead silicate W-type fiber . An improvement in the Error Vector Magnitude (EVM) and a reduction of almost a factor of 2 in the phase noise of the signal after regeneration for various noise levels at the input have been achieved. The low and flat dispersion profile of the fiber across the C-band could be potentially useful in applications requiring wavelength multicasting.
- Frequency comb generation. A. A. Savchenkov and coworkers have shown theoretically  that generation of optical frequency combs in resonators with Kerr nonlinearity and small group velocity dispersion, as previously observed in several experiments, is the result of linear interaction of resonator modes. The interaction changes the frequency of resonator modes resulting in soft excitation of the comb. The authors measured GVD of several whispering gallery mode (WGM) resonators and showed that mode crossing is sufficient to explain the observed comb generation. The theoretical framework developed in this study could be applied to a wide range of nonlinear micro-resonators.
- An example of generation of a frequency comb is described in . Namely, K. Saha and coworkers report the experimental demonstration of broadband frequency comb generation from a single-frequency pump laser at 1-mm. The result is obtained using a high-Q silicon-nitride 115 mm radius ring resonator. The resonator dispersion is engineered to have a broad anomalous group velocity dispersion region near the pump wavelength for efficient parametric four-wave mixing. The comb spans 55 THz with a 230-GHz free spectral range. These results may have applications in spectroscopy, metrology, high-speed communications, and on-chip optical clocks.
- Microring resonators and their use in making mode-locked lasers are considered by A. Pasquazi and coworkers in . The dual-mode locked laser based on an integrated high-Q microring resonator created by the authors exhibits stable operation with the output in the form of two slightly shifted spectral optical comb replicas, generating a highly monochromatic radio frequency tone of 65.8MHz with a linewidth < 10 kHz on a 200 GHz output pulse train.
- Polarization control and vector solitons. B. Stiller and coworkers report in  the observation of all-optical polarization pulling of an initially polarization-scrambled signal using parametric amplification in a highly nonlinear optical fiber. In this work, broadband polarization pulling has been achieved both for the signal and idler waves with up to 25 dB gain using the strong polarization sensitivity of parametric amplifiers. The authors also derived the probability distribution function for the final polarisation state, assuming a randomly polarized initial state.
- S. V. Sergeyev and coworkers experimentally found  new types of vector solitons with locked and slowly evolving states of polarization on a time scale of 40-40000 round-trips for fundamental soliton and multi-pulsing operations in erbium-doped fiber laser passively mode locked with carbon nanotubes. These results can find applications in secure communications, trapping and manipulation of atoms and nanoparticles and vectorial control of magnetization.
- Graphene as a saturable absorber. In , Y. F. Song and coworkers study experimentally polarization rotation vector solitons in a fiber ring laser passively mode locked with the use of graphene. The authors have shown that two extra sets of spectral sidebands always appear in the soliton spectrum of the polarization rotating vector solitons which have the same formation mechanism as well known Kelly sidebands.
- M. Oya et al propose, in , to use graphene in a Mach-Zehnder interferometer to achieve all optical switching. The switching is achieved by using saturable absorption properties of the graphene. The authors theoretically analyzed switching characteristics and used the finite-difference beam propagation method (FD-BPM) for numerical simulations. The loss of 10.2 dB in the switch is expected since only absorption is used to achieve switching operation. On the other hand, the device can work in the picosecond regime due to the fast response time of graphene.
- Supercontinuum generation and ultra-short pulses. H. Du and coworkers suggest theoretically a method for generation of broadband supercontinuum . They show that a weak few cycle pulse at 400 nm can be used to replace the ultraviolet attosecond pulse for controlling the ionization dynamics of the electron wave packets. Adding a 400-nm few cycle laser pulse to a 2000-nm driving pulse at proper time may lead to the efficient generation of a broadband supercontinuum. The attosecond pulse generated this way may have a divergence angle of about 0.1 mrad in the far field.
- D. Puris and coworkers in  presented a theoretical time-domain model for a quantum dot semiconductor optical amplifier that allowed them to simulate sub-picosecond pulse propagation. The authors presented static results including amplified spontaneous emission spectra, continuous wave amplification, and four-wave mixing experiments. The dynamic pump-probe simulations are also presented for various values of injection current. Their model used digital filters to describe the frequency dependent gain and microscopically calculated carrier-carrier scattering rates for the inter-band carrier dynamics. The model can be used to calculate the propagation of multiple signals with different wavelengths or one wide-band signal with high bit-rate.
- S. Smirnov and coworkers in  have found new transient lasing regime between stable single-pulse generation and noise-like generation in an all-normal-dispersion fibre laser mode-locked due to nonlinear polarization rotation. They identified three regimes of single pulse generation per round trip. From practical point of view, the optical phase also fluctuates. This results in temporal jitter of instantaneous frequency and limits considerably compression ratio of such pulses.
- Materials. The search for novel highly nonlinear materials, or the application of novel materials, has always been one of the major subjects at Nonlinear Photonics meetings. Certain aspects of scale-free optics are discussed by J. Parravicini and coworkers discuss in . Namely, the authors demonstrate rejuvenation in scale-free optical propagation which happens due to the glassy nature of dielectric polar-nano-regions inside the crystal. This phenomenon is caused by the non-ergodic relaxation of the dipolar glass that mediates the photorefractive nonlinearity in compositionally disordered lithium-enriched potassium tantalate- niobate (KTN:Li). Rejuvenation can halt ageing in the dipolar glass and extend the duration of beam diffraction cancellation. The results of this work show how optics can make use of out-of-equilibrium solid-state mechanisms.
- S. Gentilini and coworkers in  investigated the far field of a spatial dispersive shock wave generated from a Gaussian beam propagating in nonlinear nonlocal colloidal disordered media. The authors observed the shock above a certain amount of nonlinearity and below a critical strength of disorder. These phenomena can be quantified by measuring the threshold power in terms of the strength of randomness, controlled by the concentrations of colloidal suspension.
- Photonic crystals. In  P. Grinberg and coworkers have demonstrated that the Q factor of a 2D photonic crystal nanocavity may be increased by two orders of magnitude by the combined action of strong coherent population oscillations and increasing the nonlinear refractive index. The nanocavity is a hexagonal air hole lattice in a InP membrane. The authors have shown that at the resonance wavelength, the enhancement of the Q factor depends strongly on the pump power used in the cavity.
- Finally, M. Boguslawski and coworkers introduced, in , a method to optically induce multi-periodic photonic complex superstructures with two-dimensional refractive index modulations of the size of several centimeters. These superstructures result from the superposition of 2D fundamental periodic structures. The authors combined particular spatial frequencies of the respective Fourier series expansions in order to create the desired multi-periodic structures. As particular examples, they presented 2D photonic staircase, hexagonal wire mesh and ratchet structures. These structures are confirmed by phase resolving methods developed in digital-holography.
We would also like to mention that the success of the Nonlinear Photonics meeting in Colorado Springs this year has been largely due to the efforts of its General Chairs Prof. Wieslaw Krolikowski from the ANU and Prof. Frank Wise from Cornell University and the Program Chair of the conference Prof. John Dudley from the Université de Franche-Comte, France.
The organizers of the conference warmly invite scientists to the next meeting “Nonlinear Photonics” which will be held in Barcelona in 2014.
The work of NA is supported by the Australian Research Council.
References and links
1. Optics & Photonics Congress “Advanced Photonics,” 17–21 June 2012, Colorado Springs, Colorado, USA (OSA Technical Digest, Washington DC, 2012), ISBN 978–1-55752–946–6.
2. D. Shayovitz, H. Herrmann, W. Sohler, R. Ricken, C. Silberhorn, and D. M. Marom, “High resolution time-tospace conversion of sub-picosecond pulses at 1.55um by non-degenerated SFG in PPLN crystal,” Opt. Express 20(24), 27388–27395 (2012).
3. M. Ahlawat, A. Tehranchi, K. Pandiyan, M. Cha, and R. Kashyap, “Tunable all-optical wavelength broadcasting in a PPLN with multiple QPM peaks,” Opt. Express 20(24), 27425–27433 (2012).
4. N. Gutman, A. A. Sukhorukov, F. Eilenberger, and C. M. de Sterke, “Bistability suppression and low threshold switching using frozen light at a degenerate band edge waveguide,” Opt. Express 20(24), 27363–27368 (2012).
5. M. Heinrich, F. Eilenberger, R. Keil, F. Dreisow, E. Suran, F. Louradour, A. Tunnermann, T. Pertsch, S. Nolte, and A. Szameit, “Optical limiting and spectral stabilization in segmented photonic lattices,” Opt. Express 20(24), 27299–27310 (2012).
6. G. Huang, Y. Miyoshi, A. Maruta, and K. Kitayama, “All-optical technique for modulation format conversion from NRZ-OOK to RZ-160AM employing nonlinear optical loop mirror with 1:2 coupler,” Opt. Express 20(24), 27311–27321 (2012).
7. G. Fanjoux, E. Lantz, J. Michaud, and T. Sylvestre, “Beam steering using optical parametric amplification in Kerr medium: a space-time analogy of parametric slow-light,” Opt. Express 20(24), 27396–27402 (2012).
8. D. Ramirez Martinez, M. M. Mendez Otero, M. L. Arroyo Carrasco, and M. D. Iturbe Castillo, “Waveguide properties of the asymmetric collision between two bright spatial solitons in Kerr media,” Opt. Express 20(24), 27411–27418 (2012).
9. A. S. Solntsev, A. A. Sukhorukov, D. N. Neshev, and Y. S. Kivshar, “Photon-pair generation in arrays of cubic nonlinear waveguides,” Opt. Express 20(24), 27441–27446 (2012).
10. K. Krupa, A. Tonello, V. V. Kozlov, V. Couderc, P. D. Bin, S. Wabnitz, A. Barthelemy, L. Labonte, and S. Tanzilli, “Bragg-scattering conversion at telecom wavelengths in the photon counting regime,” Opt. Express 20(24), 27220–27225 (2012).
11. V. V. Kozlov, J. Nuño, J. D. Ania-Castañon, and S. Wabnitz, “Analytic theory of fiber-optic Raman polarizers,” Opt. Express 20(24), 27242–27247 (2012).
12. J. Nuño, M. Alcon-Camas, and J. D. Ania-Castañon, “RIN transfer in random distributed feedback fiber lasers,” Opt. Express 20(24), 27376–27381 (2012).
13. L. Mejling, D. S. Cargill, C. J. McKinstrie, K. Rottwitt, and R. O. Moore, “Effects of nonlinear phase modulation on Bragg scattering in the low-conversion regime,” Opt. Express 20(24), 27454–27475 (2012). [PubMed]
14. L. Jin, B. Xu, and S. Yamashita, “Alleviation of additional phase noise in fiber optical parametric amplifier based signal regenerator,” Opt. Express 27254–27264 (2012). [PubMed]
15. A. A. Vedadi, M. A. Shoaie, and C.-S. Br’es, “Experimental investigation of pulse generation with one-pump fiber optical parametric amplification,” Opt. Express 20(24), 27344–27354 (2012).
16. M. A. Ettabib, F. Parmigiani, X. Feng, L. Jones, J. Kakande, R. Slavik, F. Poletti, G. M. Ponzo, J. Shi, M. N. Petrovich, W. H. Loh, P. Petropoulos, and D. J. Richardson, “Phase regeneration of DPSK signals in a highly nonlinear lead-silicate W-type fiber,” Opt. Express 20(24), 27419–27424 (2012).
17. A. A. Savchenkov, A. B. Matsko, W. Liang, V. S. Ilchenko, D. Seidel, and L. Maleki, “Kerr frequency comb generation in overmoded resonators,” Opt. Express 20(24), 27290–27298 (2012).
18. K. Saha, Y. Okawachi, J. S. Levy, R. K. W. Lau, K. Luke, M. A. Foster, M. Lipson, and A. L. Gaeta, “Broadband parametric frequency comb generation with a 1-mm pump source,” Opt. Express 20(24), 26935–26941 (2012). [CrossRef]
19. A. Pasquazi, M. Peccianti, B. E. Little, S. T. Chu, D. J. Moss, and R. Morandotti, “Stable, dual mode, high repetition rate mode-locked laser based on a microring resonator,” Opt. Express 20(24), 27355–27362 (2012).
20. B. Stiller, P. Morin, D. M. Nguyen, J. Fatome, S. Pitois, E. Lantz, H. Maillotte, C. R. Menyuk, and T. Sylvestre, “Demonstration of polarization pulling using a fiber-optical parametric amplifier,” Opt. Express 20(24), 27248–27253 (2012).
21. S. V. Sergeyev, C. Mou, A. Rozhin, and S. K. Turitsyn, “Vector solitons with locked and precessing states of polarization,” Opt. Express 20(24), 27434–27440 (2012).
22. Y. F. Song, H. Zhang, D. Y. Tang, and D. Y. Shen, “Polarization rotation vector solitons in a grapheme modelocked fibre laser,” Opt. Express 20(24), 27283–27289 (2012).
23. M. Oya, H. Kishikawa, N. Goto, and S. Yanagiya, “All-optical switch consisting of two-stage interferometers controlled by using saturable absorption of monolayer graphene,” Opt. Express 20(24), 27322–27330 (2012).
24. H. Du, L. Luo, X. Wang, and B. Hu, “Attosecond ionization control for broadband supercontinuum generation using a week 400-nm few-cycle controlling pulse,” Opt. Express 20(24), 27226–27241 (2012).
25. D. Puris, C. Schmidt Langhorst, K. Ludge, N. Majer, E. Scholl, and K. Petermann, “Time-domain model of quantum-dot semiconductor optical amplifiers for wideband optical signals,” Opt. Express 20(24), 27265–27282 (2012).
26. S. Smirnov, S. Kobtsev, S. Kukarin, and A. Ivanenko, “Three key regimes of single pulse generation per round trip of all-normal-dispersion fiber lasers mode-locked with nonlinear polarization rotation,” Opt. Express 20(24), 27447–27453 (2012).
27. J. Parravicini, C. Conti, A. J. Agranat, and E. DelRe, “Rejuvenation in scale-free optics and enhanced diffraction cancellation life-time,” Opt. Express 20(24), 27382–27387 (2012).
28. S. Gentilini, N. Ghofraniha, E. DelRe, and C. Conti, “Shock wave far-field in ordered and disordered nonlocal media,” Opt. Express 20(24), 27369–27375 (2012).
29. P. Grinberg, K. Bencheikh, M. Brunstein, A. M. Yacomotti, Y. Dumeige, I. Sagnes, F. Raineri, L. Bigot, and J. A. Levenson, “Enhancement of a nano cavity lifetime by induced slow light and nonlinear dispersions,” Opt. Express 20(24), 27403–27410 (2012).
30. M. Boguslawski, A. Kelberer, P. Rose, and C. Denz, “Multiplexing complex two-dimensional photonic superlattices,” Opt. Express 20(24), 27331–27343 (2012).