publications

2008

1. Z-scan studies and optical limiting of nanosecond laser pulses in neutral red dye

   George, Mathew, Muneera, C.I., Singh, C.P., Bindra, K.S., and Oak, S.M.

   Optics & Laser Technology 2008

   Abs Bib

   The nonlinear optical absorption, refraction and optical limiting behaviour of an organic dye, neutral red, were investigated under excitation with nanosecond laser pulses at 532nm. The nonlinear optical responses of the material were studied both in solution and solid film, made in methanol and polyvinyl alcohol, respectively, using single-beam Z-scan technique. The open aperture Z-scans of the solution samples displayed a switch over from saturable absorption to enhanced absorption with increase in input intensity. Theoretical fit to the experimental data indicated that the dominant mechanism of nonlinear absorption is two-photon absorption. The closed aperture Z-scans of both the samples denoted positive nonlinearity, which was three orders larger in magnitude in solid film, compared with that in solution. The results of optical limiting experiments revealed that neutral red exhibited strong optical limiting of nanosecond laser pulses with a threshold lower than that of C60 in toluene.

   @article{GEORGE2008373,
     title = {Z-scan studies and optical limiting of nanosecond laser pulses in neutral red dye},
     journal = {Optics & Laser Technology},
     bibtex_show = {true},
     volume = {40},
     number = {2},
     pages = {373-378},
     year = {2008},
     issn = {0030-3992},
     doi = {https://doi.org/10.1016/j.optlastec.2007.06.008},
     url = {https://www.sciencedirect.com/science/article/pii/S0030399207001028},
     author = {George, Mathew and Muneera, C.I. and Singh, C.P. and Bindra, K.S. and Oak, S.M.},
     keywords = {Nonlinear optical absorption, Neutral red, Optical limiting}
   }

2010

1. Spectroscopic investigations of a Ti:Tm:LiNbO3 waveguide for photon-echo quantum memory

   Sinclair, N., Saglamyurek, E., George, M., Ricken, R., {La Mela}, C., Sohler, W., and Tittel, W.

   Journal of Luminescence 2010

   Abs Bib

   We report the fabrication and characterization of a Ti4+:Tm3+:LiNbO3 optical waveguide in view of photon-echo quantum memory applications. Specifically, we investigated room- and cryogenic-temperature properties of the waveguide, and the Tm3+ ions, via absorption, spectral hole burning, photon echo, and Stark spectroscopy. For the Tm3+ ions, we found radiative lifetimes of 82μs and 2.4ms for the H43 and F43 levels, respectively, and a 44% branching ratio from the H43 to the F43 level. We also measured an optical coherence time of 1.6μs for the H63↔H43, 795nm wavelength transition, and investigated the limitation of spectral diffusion to spectral hole burning. Upon application of magnetic fields of a few hundred Gauss, we observed persistent spectral holes with lifetimes up to seconds. Furthermore, we measured a linear Stark shift of 25kHzcm/V. Our results are promising for integrated, electro-optical, waveguide quantum memory for photons.

   @article{SINCLAIR20101586,
     title = {Spectroscopic investigations of a Ti:Tm:LiNbO3 waveguide for photon-echo quantum memory},
     journal = {Journal of Luminescence},
     bibtex_show = {true},
     volume = {130},
     number = {9},
     pages = {1586-1593},
     year = {2010},
     note = {Special Issue based on the Proceedings of the Tenth International Meeting on Hole Burning, Single Molecule, and Related Spectroscopies: Science and Applications (HBSM 2009) - Issue dedicated to Ivan Lorgere and Oliver Guillot-Noel},
     issn = {0022-2313},
     doi = {https://doi.org/10.1016/j.jlumin.2009.12.022},
     url = {https://www.sciencedirect.com/science/article/pii/S0022231309006243},
     author = {Sinclair, N. and Saglamyurek, E. and George, M. and Ricken, R. and {La Mela}, C. and Sohler, W. and Tittel, W.},
     keywords = {Rare-earth-ion doped crystals,  waveguides, Photon-echo, Spectral hole burning, Optical coherence, Quantum communication, Quantum memory}
   }

2011

1. Broadband waveguide quantum memory for entangled photons

   Saglamyurek, Erhan, Sinclair, Neil, Jin, Jeongwan, Slater, Joshua A., Oblak, Daniel, Bussi{\`e}res, F{\'e}lix, George, Mathew, Ricken, Raimund, Sohler, Wolfgang, and Tittel, Wolfgang

   Nature 2011

   Abs Bib

   Harnessing entanglement between light and material systems is of interest for future quantum information technologies. Two groups report advances in the development of the light--matter quantum interface that could pave the way for the construction of multiplexed quantum repeaters for long-distance quantum networks. Clausen et al. demonstrate entanglement between a photon at the telecommunication wavelength (1,338 nanometres) and a single collective atomic excitation stored in a neodymium-doped Y2SiO5 crystal. Saglamyurek et al. use a thulium-doped LiNbO3 waveguide to achieve a similar entanglement.

   @article{Saglamyurek2011,
     author = {Saglamyurek, Erhan and Sinclair, Neil and Jin, Jeongwan and Slater, Joshua A. and Oblak, Daniel and Bussi{\`e}res, F{\'e}lix and George, Mathew and Ricken, Raimund and Sohler, Wolfgang and Tittel, Wolfgang},
     title = {Broadband waveguide quantum memory for entangled photons},
     journal = {Nature},
     bibtex_show = {true},
     year = {2011},
     month = jan,
     day = {01},
     volume = {469},
     number = {7331},
     pages = {512-515},
     selected = {true},
     issn = {1476-4687},
     doi = {10.1038/nature09719},
     url = {https://doi.org/10.1038/nature09719}
   }

2012

1. Conditional Detection of Pure Quantum States of Light after Storage in a Tm-Doped Waveguide

   Saglamyurek, Erhan, Sinclair, Neil, Jin, Jeongwan, Slater, Joshua A., Oblak, Daniel, Bussi\`eres, F\'elix, George, Mathew, Ricken, Raimund, Sohler, Wolfgang, and Tittel, Wolfgang

   Phys. Rev. Lett. 2012

   Bib

   @article{PhysRevLett.108.083602,
     title = {Conditional Detection of Pure Quantum States of Light after Storage in a Tm-Doped Waveguide},
     author = {Saglamyurek, Erhan and Sinclair, Neil and Jin, Jeongwan and Slater, Joshua A. and Oblak, Daniel and Bussi\`eres, F\'elix and George, Mathew and Ricken, Raimund and Sohler, Wolfgang and Tittel, Wolfgang},
     journal = {Phys. Rev. Lett.},
     bibtex_show = {true},
     volume = {108},
     issue = {8},
     pages = {083602},
     numpages = {5},
     year = {2012},
     month = feb,
     publisher = {American Physical Society},
     doi = {10.1103/PhysRevLett.108.083602},
     url = {https://link.aps.org/doi/10.1103/PhysRevLett.108.083602}
   }

2013

1. In-band pumped Ti:Tm:LiNbO3 waveguide amplifier and low threshold laser

   George, Mathew, Ricken, Raimund, Quiring, Viktor, and Sohler, Wolfgang

   Laser \& Photonics Reviews 2013

   Abs Bib

   Abstract The fabrication by diffusion doping and a detailed optical investigation of a Ti:Tm:LiNbO3 waveguide amplifier and of a Fabry-Pérot type Ti:Tm:LiNbO3 laser are reported. Both devices are in-band pumped by a laser diode at 1650 nm. The wave-guide amplifier shows broad-band optical gain in the wavelength range 1750 nm < λ < 1900 nm. The laser emits at 1890 nm, the longest emission wavelength of a Tm:LiNbO3 laser reported so far; also 1850 nm emission could be demonstrated. Laser threshold (1890 nm) is at 4 mW coupled pump power; the slope efficiency is ∼13.3\%. Properties and potential of both devices are analyzed by extensive modeling.

   @article{https://doi.org/10.1002/lpor.201200063,
     author = {George, Mathew and Ricken, Raimund and Quiring, Viktor and Sohler, Wolfgang},
     title = {In-band pumped Ti:Tm:LiNbO3 waveguide amplifier and low threshold laser},
     journal = {Laser \& Photonics Reviews},
     bibtex_show = {true},
     selected = {true},
     volume = {7},
     number = {1},
     pages = {122-131},
     keywords = {Integrated Optics, Lithium niobate, Optical amplifiers, Rare earth and transition metal solid-state lasers, Diode pumped lasers},
     doi = {https://doi.org/10.1002/lpor.201200063},
     url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lpor.201200063},
     eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/lpor.201200063},
     year = {2013}
   }

2. Two-photon interference of weak coherent laser pulses recalled from separate solid-state quantum memories

   Jin, Jeongwan, Slater, Joshua A., Saglamyurek, Erhan, Sinclair, Neil, George, Mathew, Ricken, Raimund, Oblak, Daniel, Sohler, Wolfgang, and Tittel, Wolfgang

   Nature Communications 2013

   Abs Bib

   Quantum memories allowing reversible transfer of quantum states between light and matter are central to quantum repeaters, quantum networks and linear optics quantum computing. Significant progress regarding the faithful transfer of quantum information has been reported in recent years. However, none of these demonstrations confirm that the re-emitted photons remain suitable for two-photon interference measurements, such as C-NOT gates and Bell-state measurements, which constitute another key ingredient for all aforementioned applications. Here, using pairs of laser pulses at the single-photon level, we demonstrate two-photon interference and Bell-state measurements after either none, one or both pulses have been reversibly mapped to separate thulium-doped lithium niobate waveguides. As the interference is always near the theoretical maximum, we conclude that our solid-state quantum memories, in addition to faithfully mapping quantum information, also preserve the entire photonic wavefunction. Hence, our memories are generally suitable for future applications of quantum information processing that require two-photon interference.

   @article{Jin2013,
     author = {Jin, Jeongwan and Slater, Joshua A. and Saglamyurek, Erhan and Sinclair, Neil and George, Mathew and Ricken, Raimund and Oblak, Daniel and Sohler, Wolfgang and Tittel, Wolfgang},
     title = {Two-photon interference of weak coherent laser pulses recalled from separate solid-state quantum memories},
     journal = {Nature Communications},
     bibtex_show = {true},
     selected = {true},
     year = {2013},
     month = aug,
     day = {29},
     volume = {4},
     number = {1},
     pages = {2386},
     issn = {2041-1723},
     doi = {10.1038/ncomms3386},
     url = {https://doi.org/10.1038/ncomms3386}
   }

2014

1. Spectral Multiplexing for Scalable Quantum Photonics using an Atomic Frequency Comb Quantum Memory and Feed-Forward Control

   Sinclair, Neil, Saglamyurek, Erhan, Mallahzadeh, Hassan, Slater, Joshua A., George, Mathew, Ricken, Raimund, Hedges, Morgan P., Oblak, Daniel, Simon, Christoph, Sohler, Wolfgang, and Tittel, Wolfgang

   Phys. Rev. Lett. 2014

   Bib

   @article{PhysRevLett.113.053603,
     title = {Spectral Multiplexing for Scalable Quantum Photonics using an Atomic Frequency Comb Quantum Memory and Feed-Forward Control},
     author = {Sinclair, Neil and Saglamyurek, Erhan and Mallahzadeh, Hassan and Slater, Joshua A. and George, Mathew and Ricken, Raimund and Hedges, Morgan P. and Oblak, Daniel and Simon, Christoph and Sohler, Wolfgang and Tittel, Wolfgang},
     journal = {Phys. Rev. Lett.},
     bibtex_show = {true},
     volume = {113},
     issue = {5},
     pages = {053603},
     numpages = {5},
     year = {2014},
     month = jul,
     publisher = {American Physical Society},
     doi = {10.1103/PhysRevLett.113.053603},
     url = {https://link.aps.org/doi/10.1103/PhysRevLett.113.053603}
   }