Stimulated Raman Scattering (SRS) in α‐AlOOH (Diaspore)

In single crystals of orthorhombic α‐AlOOH, known also as mineral diaspore, χ(3)‐nonlinear lasing by stimulated Raman scattering (SRS) and Raman‐induced four‐wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 µm wavelength produces a broadband Stokes and anti‐Stokes frequency comb with up to 25 SRS‐ and RFWM‐generated emission lines. All observed Stokes and anti‐Stokes lasing components in the visible and near‐IR are identified and attributed to a single SRS‐promoting vibration mode with ωSRS ≈ 445 cm−1. The first Stokes steady‐state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW−1

High-speed integrated QKD system

Quantum key distribution (QKD) is nowadays a well established method for generating secret keys at a distance in an information-theoretic secure way, as the secrecy of QKD relies on the laws of quantum physics and not computational complexity. In order to industrialize QKD, low-cost, mass-manufactured and practical QKD setups are required. Hence, photonic and electronic integration of the sender's and receiver's respective components is currently in the spotlight. Here we present a high-speed (2.5 GHz) integrated QKD setup featuring a transmitter chip in silicon photonics allowing for high-speed modulation and accurate state preparation, as well as a polarization-independent low-loss receiver chip in aluminum borosilicate glass fabricated by the femtosecond laser micromachining technique. Our system achieves raw bit error rates, quantum bit error rates and secret key rates equivalent to a much more complex state-of-the-art setup based on discrete components

Compact, High-Speed Mach-Zehnder Modulator With On-Chip Linear Drivers in Photonic BiCMOS Technology

A monolithically integrated electronic-photonic Mach-Zehnder modulator is presented, incorporating electronic linear drivers along with photonic components. Electro-optical 3 dB & 6 dB bandwidths of 24 GHz and 34 GHz, respectively, were measured. The measurements are in good agreement with electronic-photonic post-layout simulation results and verify the design methodology. A full $\pi$ phase shift was achieved by applying a differential input voltage of $V_{\pi } =$ 420 mV to the driver input, effectively decreasing the required modulation voltage by a factor of approximately 10

Stimulated Raman Scattering (SRS) in alpha-AlOOH (Diaspore)

In single crystals of orthorhombic alpha-AlOOH, known also as mineral diaspore, chi((3))-nonlinear lasing by stimulated Raman scattering (SRS) and Raman-induced four-wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 mu m wavelength produces a broadband Stokes and anti-Stokes frequency comb with up to 25 SRS- and RFWM-generated emission lines. All observed Stokes and anti-Stokes lasing components in the visible and near-IR are identified and attributed to a single SRS-promoting vibration mode with omega(SRS) approximate to 445 cm(-1). The first Stokes steady-state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW(-1)

Observation of χ(3)-nonlinear optical effects in stimulated Raman scattering (SRS)-active CsLa(WO4)2 crystals: high-order Stokes and anti-Stokes generation and self-Raman CsLa(WO4)2:Nd3+ laser converter

Tetragonal tungstate CsLa(WO4)2:Nd was found to be an attractive multifunctional simultaneously Nd-laser and stimulated Raman scattering (SRS)-active crystal. A multitude of Stokes and anti-Stokes components is generated in the visible and near-infrared spectral region producing frequency combs with widths of ~8600 cm-1 and ~9560 cm-1 under pumping at 0.53207 µm and 1.06415 µm wavelengths, respectively. All registered nonlinear emission lines are identified and attributed to a single SRS-promoting vibration νs(WO4) mode with energy of ωSRS ~956 cm-1. Moreover, a passively Q-switched LD-pumped nanosecond self-Raman CsLa(WO4)2:Nd laser is reported. An overview of Ln-doped tungstate self-Raman lasers is given as well

Stimulated Raman scattering in natural crystals of fluorapatite, Ca-5(PO4)(3)F

Hexagonal Ca-5(PO4)(3)F, known as natural crystal fluorapatite and oldest host-crystal for Ln(3+)-lasant ions, is presented as a Raman-active material. High-order Raman-induced.(3)-nonlinear processes are discovered in natural crystals of fluorapatite under picosecond pumping at 1.064 mu m and 0.532 mu m wavelength. A multitude of Stokes and anti-Stokes components is generated in the ultraviolet, visible and near-infrared spectral region by stimulated Raman scattering (SRS) and Raman four-wave mixing (FWHM), resulting in a frequency comb with a width of 520 THz. The spectral lines are identified and attributed to the nu(1)(A(g)) vibration mode of the tetrahedral [PO4] units which is related to a Raman shift of omega(SRS) approximate to 965 cm(-1). The first Stokes steady-state Raman gain coefficient in the near-infrared spectral range is estimated to be > 0.38 cm.GW(-1). Finally, a short review of SRS-promoting vibration modes and observed.(3)-nonlinear interactions in all known SRS-active natural crystals (minerals) is given

Zircon, ZrSiO4 - A novel SRS-active crystal

The discovery of chi((3))-nonlinear lasing by stimulated Raman scattering (SRS) in natural crystals of zircon, ZrSiO4, is reported. All recorded Stokes and anti-Stokes Raman-induced lasing components are identified and attributed to the two occurring SRS-promoting phonon modes with omega(SRS1) approximate to 1008 cm(-1) and omega(SRS2) approximate to 356 cm(-1), which are related to the anti-symmetric stretching vibration B-1g(nu(3)) and the bending mode E-g(nu(4)), respectively, of the crystal with symmetry D-4h(19) = I4(1)/amd. The study indicates the high potential of ZrSiO4 as an effective SRS crystal. [GRAPHICS] Crystals of ZrSiO4, as used for sample preparation, together with a sample for SRS measurement. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Spodumene, alpha-LiAlSi2O6 - A new natural SRS-active crystal with three chi((3))-promoting vibrational modes

alpha-LiAlSi2O6, known as mineral spodumene, is introduced as a novel SRS-active crystal with monoclinic symmetry C2/c. Under picosecond laser excitation Raman-induced steady-state chi((3))-nonlinear generation in the visible and near-IR is observed in the crystals. All recorded Stokes and anti-Stokes high-order lasing components are identified and correspond to three SRS-promoting phonon modes with omega(SRS1) approximate to 709 cm(-1), omega(RSR2) approximate to 357 cm(-1) and omega(SRS3) approximate to 1074 cm(-1). On the basis of the results of a spontaneous Raman scattering study they were assigned to vibrations of the tetrahedral [SiO4] groups of the silicate chains and lattice modes of Li-O or Al-O of the crystal structure. A brief review in tabular form of so far known SRS-active natural crystals (minerals) is given as well. (C) 2018 Elsevier B.V. All rights reserved

High-speed integrated QKD system

Quantum key distribution (QKD) is nowadays a well-established method for generating secret keys at a distance in an information-theoretically secure way, as the secrecy of QKD relies on the laws of quantum physics and not on computational complexity. In order to industrialize QKD, low-cost, mass-manufactured, and practical QKD setups are required. Hence, photonic and electronic integration of the sender’s and receiver’s respective components is currently in the spotlight. Here we present a high-speed (2.5 GHz) integrated QKD setup featuring a transmitter chip in silicon photonics allowing for high-speed modulation and accurate state preparation, as well as a polarization-independent low-loss receiver chip in aluminum borosilicate glass fabricated by the femtosecond laser micromachining technique. Our system achieves raw bit error rates, quantum bit error rates, and secret key rates equivalent to a much more complex state-of-the-art setup based on discrete components [Boaron A. et al. , Phys. Rev. Lett. 121 , 190502 (2018)].</p