Flatband slow light in photonic crystals featuring spatial pulse compression and terahertz bandwidth.

Paradoxically, slow light promises to increase the speed of telecommunications in novel photonic structures, such as coupled resonators [1] and photonic crystals [2,3]. Apart from signal delays, the key consequence of slowing light down is the enhancement of light-matter interactions. Linear effects such as refractive index modulation scale linearly with slowdown in photonic crystals [3], and nonlinear effects are expected to scale with its square [4]. By directly observing the spatial compression of an optical pulse, by factor 25, we confirm the mechanism underlying this square scaling law. The key advantage of photonic structures over other slow light concepts is the potentially large bandwidth, which is crucial for telecommunications [5]. Nevertheless, the slow light previously observed in photonic crystals [2,3,6,7] has been very dispersive and featured narrow bandwidth. We demonstrate slow light with a bandwidth of 2.5 THz and a delay-bandwidth product of 30, which is an order of magnitude larger than any reported so far.

[1]  C. Chang-Hasnain,et al.  Slow-light in semiconductor quantum wells , 2004, InternationalQuantum Electronics Conference, 2004. (IQEC)..

[2]  Manfred Eich,et al.  Zero dispersion at small group velocities in photonic crystal waveguides , 2004 .

[3]  M. Notomi,et al.  Extremely large group-velocity dispersion of line-defect waveguides in photonic crystal slabs. , 2001, Physical review letters.

[4]  M. Notomi,et al.  Waveguides, resonators and their coupled elements in photonic crystal slabs. , 2004, Optics express.

[5]  M Miyagi,et al.  Pulse spreading in a single-mode fiber due to third-order dispersion. , 1979, Applied optics.

[6]  Jacob B. Khurgin,et al.  Optical buffers based on slow light in electromagnetically induced transparent media and coupled resonator structures: comparative analysis , 2005 .

[7]  H. Hamann,et al.  Active control of slow light on a chip with photonic crystal waveguides , 2005, Nature.

[8]  Yoshimasa Sugimoto,et al.  The effect of higher-order dispersion on slow light propagation in photonic crystal waveguides. , 2006 .

[9]  Jeff F. Young,et al.  Extrinsic optical scattering loss in photonic crystal waveguides: role of fabrication disorder and photon group velocity. , 2005, Physical review letters.

[10]  J. D. Joannopoulos,et al.  Enhancement of nonlinear effects using photonic crystals , 2004, Nature materials.

[11]  Yurii A Vlasov,et al.  Coupling into the slow light mode in slab-type photonic crystal waveguides. , 2006, Optics letters.

[12]  Steven G. Johnson,et al.  Adiabatic theorem and continuous coupled-mode theory for efficient taper transitions in photonic crystals. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[13]  J P Korterik,et al.  Direct observation of Bloch harmonics and negative phase velocity in photonic crystal waveguides. , 2005, Physical review letters.

[14]  T. Krauss,et al.  Real-space observation of ultraslow light in photonic crystal waveguides. , 2005, Physical review letters.

[15]  Mario Martinelli,et al.  Linear and nonlinear pulse propagation in coupled resonator slow-wave optical structures , 2003 .

[16]  Jacob Fage-Pedersen,et al.  Photonic crystal waveguides with semi-slow light and tailored dispersion properties. , 2006, Optics express.

[17]  L. Kuipers,et al.  The effect of higher order dispersion on slow light propagation in photonic crystal waveguides , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[18]  J P Korterik,et al.  Tracking Femtosecond Laser Pulses in Space and Time , 2001, Science.

[19]  Yoshitomo Okawachi,et al.  Wide bandwidth slow light using a Raman fiber amplifier. , 2005, Optics express.

[20]  T. Krauss,et al.  Low loss silicon on insulator photonic crystal waveguides made by 193nm optical lithography. , 2006, Optics express.