November 2013 Volume 7, Issue 11

Editorial

Fibre laser focus   p841
doi:10.1038/nphoton.2013.292
With their ultrafast and high-power characteristics, fibre lasers are penetrating conventional laser markets as well as opening up exciting new opportunities.

Commentary

Nanotube and graphene saturable absorbers for fibre lasers   pp842 - 845
Amos Martinez and Zhipei Sun
doi:10.1038/nphoton.2013.304
Nanotubes and graphene have emerged as promising materials for use in ultrafast fibre lasers. Their unique electrical and optical properties enable them to be used as saturable absorbers that have fast responses and broadband operation and that can be easily integrated in fibre lasers.

Interviews

Fibre laser directions   pp846 - 847
Interview with Anatoly Grudinin
doi:10.1038/nphoton.2013.306
Nature Photonics spoke to Anatoly Grudinin, founder of the fibre laser company Fianium, to gain insight into the vicissitudes in the industry over the past decade and future challenges that academia can help solve.

Research Highlights

Materials: Smart glass | Biophotonics: Gene expression control | Plasmonics: Nonlocality simplified | Optical clocks: Record stability | Reciprocity: Magnets not needed | Liquid crystals: Nanosecond switching | Superluminescent diodes: High-optical power | Medical diagnostics: Urine testing app | Optical beams: Vortex manipulation | Optical manipulation: Metasurface spin effect

News and Views

Reviews

High-power fibre lasers   pp861 - 867
Cesar Jauregui, Jens Limpert and Andreas Tunnermann
doi:10.1038/nphoton.2013.273
High-power fibre lasers are in demand for industrial, defence and scientific applications. This review provides an overview of the present state of the art in the field and discusses present challenges and the future outlook.

Ultrafast fibre lasers   pp868 - 874
Martin E. Fermann and Ingmar Hartl
doi:10.1038/nphoton.2013.280
Ultrafast fibre lasers are an important optical system with industrial, medical and purely scientific applications. Essential components and the operation regimes of ultrafast fibre laser systems are reviewed, as are their use in various applications.

Recent advances in fibre lasers for nonlinear microscopy   pp875 - 882
C. Xu and F. W. Wise
doi:10.1038/nphoton.2013.284
This Review discusses recent advances, and identifies challenges and opportunities regarding the use of fibre lasers in nonlinear bioimaging.

Letters

Chip-integrated ultrafast graphene photodetector with high responsivity   pp883 - 887
Xuetao Gan, Ren-Jye Shiue, Yuanda Gao, Inanc Meric, Tony F. Heinz, Kenneth Shepard, James Hone, Solomon Assefa & Dirk Englund
doi:10.1038/nphoton.2013.253
A chip-integrated graphene photodetector with a high responsivity of over 0.1 A W-1, high speed and broad spectral bandwidth is realized through enhanced absorption due to near-field coupling. Under zero-bias operation, response rates above 20 GHz and an instrumentation-limited 12 Gbit s-1 optical data link are demonstrated.

See also: News and Views by Liu & Zhang

High-responsivity graphene/silicon-heterostructure waveguide photodetectors   pp888 - 891
Xiaomu Wang, Zhenzhou Cheng, Ke Xu, Hon Ki Tsang and Jian-Bin Xu
doi:10.1038/nphoton.2013.241
A CMOS-compatible graphene/silicon-heterostructure photodetector formed by integrating graphene onto a silicon optical waveguide on silicon-on-insulator and operating in the near- and mid-infrared regions is demonstrated. A responsivity as high as 0.13 A W-1 is obtained at a bias of 1.5 V for 2.75-[mu]m light at room temperature.

See also: News and Views by Liu & Zhang

CMOS-compatible graphene photodetector covering all optical communication bands   pp892 - 896
Andreas Pospischil, Markus Humer, Marco M. Furchi, Dominic Bachmann, Romain Guider, Thomas Fromherz & Thomas Mueller
doi:10.1038/nphoton.2013.240
A CMOS-compatible photodetector based on graphene with multi-gigahertz operation ranging from the O- to U-band of telecommunication bands is demonstrated, highlighting the promise of graphene as a new material for integrated photonics.

See also: News and Views by Liu & Zhang

Nonlinear laser lithography for indefinitely large-area nanostructuring with femtosecond pulses   pp897 - 901
Bülent Öktem, Ihor Pavlov, Serim Ilday, Hamit Kalaycıoğlu, Andrey Rybak, Seydi Yavaş, Mutlu Erdoğan & F. Ömer Ilday
doi:10.1038/nphoton.2013.272
A simple, rapid and inexpensive nanolithography technique is demonstrated that exploits nonlinear feedback mechanisms to tightly regulate the formation of nanostructures induced by femtosecond laser pulses. The nonlocal nature of the feedback allows the nanostructures to be seamlessly stitched, resulting in large-area nanostructuring whose periodicity is uniform on a subnanometre scale.

Articles

Trapping light by mimicking gravitational lensing   pp902 - 906
C. Sheng, H. Liu, Y. Wang, S. N. Zhu and D. A. Genov
doi:10.1038/nphoton.2013.247
By utilizing a microstructured optical waveguide around a microsphere, an optical anlogue of the effects of gravity on the motion of light rays is demonstrated. Both far-field gravitational-lensing effects and the critical phenomenon that occurs close to the photon sphere of astrophysical objects under hydrostatic equilibrium are experimentally demonstrated.

See also: News and Views by Leonhardt

Experimental realization of an epsilon-near-zero metamaterial at visible wavelengths   pp907 - 912
Ruben Maas, James Parsons, Nader Engheta and Albert Polman
doi:10.1038/nphoton.2013.256
Silver and silicon nitride metamaterial structures with dielectric permittivities close to zero are demonstrated at visible wavelengths. In such materials, the optical phase advance during propagation can be very small.

Two-stage seeded soft-X-ray free-electron laser   pp913 - 918
E. Allaria, D. Castronovo, P. Cinquegrana, P. Craievich, M. Dal Forno, M. B. Danailov, G. D'Auria, A. Demidovich, G. De Ninno, S. Di Mitri, B. Diviacco, W. M. Fawley, M. Ferianis, E. Ferrari, L. Froehlich, G. Gaio, D. Gauthier, L. Giannessi, R. Ivanov, B. Mahieu, N. Mahne, I. Nikolov, F. Parmigiani, G. Penco, L. Raimondi, C. Scafuri, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovo, M. Veronese, D. Zangrando & M. Zangrando
doi:10.1038/nphoton.2013.277
A seeded free-electron laser with a two-stage harmonic upshift configuration provided tunable and coherent soft-X-ray pulses. The configuration produced single-transverse-mode, narrow-spectral-bandwidth femtosecond pulses with energies of several tens of microjoules and a low pulse-to-pulse wavelength jitter at wavelengths of 10.8 nm and below.

See also: News and Views by Hara

Real-time wavefront shaping through scattering media by all-optical feedback   pp919 - 924
Micha Nixon, Ori Katz, Eran Small, Yaron Bromberg, Asher A. Friesem, Yaron Silberberg & Nir Davidson
doi:10.1038/nphoton.2013.248
The self-organization of many laser modes in phase and frequency realized by minimizing radiation losses in a cavity enables the complex wavefront required to focus light scattered by turbid samples to be generated on sub-microsecond timescales without employing electronic feedback, spatial light modulators or phase-conjugation crystals.

Induced transparency by coupling of Tamm and defect states in tunable terahertz plasmonic crystals   pp925 - 930
Gregory C. Dyer, Gregory R. Aizin, S. James Allen, Albert D. Grine, Don Bethke, John L. Reno & Eric A. Shaner
doi:10.1038/nphoton.2013.252
Tamm states on subwavelength, reconfigurable plasmonic crystals are studied in the terahertz regime. By introducing an independently controlled plasmonic defect, an electromagnetically induced transparency phenomenon is revealed.

See also: Interview with Eric Shaner

Interview

Tamm states in electron plasma   p932
Interview with Eric Shaner
doi:10.1038/nphoton.2013.291
Researchers have fabricated a voltage-tunable plasmonic crystal in a two-dimensional electron gas that operates at terahertz frequencies. Nature Photonics spoke to Eric Shaner, Greg Dyer and Greg Aizin about the observation of Tamm states at the crystal's edge.