Interference of multi-mode photon echoes generated in spatially separated solid-state atomic ensembles

High-visibility interference of photon echoes generated in spatially separated solid-state atomic ensembles is demonstrated. The solid state ensembles were LiNbO$_3$ waveguides doped with Erbium ions absorbing at 1.53 $\mu$m. Bright coherent states of light in several temporal modes (up to 3) are stored and retrieved from the optical memories using two-pulse photon echoes. The stored and retrieved optical pulses, when combined at a beam splitter, show almost perfect interference, which demonstrates both phase preserving storage and indistinguishability of photon echoes from separate optical memories. By measuring interference fringes for different storage times, we also show explicitly that the visibility is not limited by atomic decoherence. These results are relevant for novel quantum repeaters architectures with photon echo based multimode quantum memories

Harmonically mode-locked Ti:Er:LiNbO3 waveguide laser

Active mode locking of an Er-diffusion-doped Ti:LiNbO3 waveguide laser by intracavity phase modulation to as high as the fourth harmonic (5.12 GHz) of the axial-mode frequency spacing is reported. The diode-pumped, pigtailed, and fully packaged laser with a monolithically integrated intracavity phase modulator has a threshold of 9 mW (incident pump power Ep jj c) and emits transform-limited pulses of >3.8-ps width and <5.6-pJ pulse energy (gain-switched mode locking) at 1602-nm wavelength (Es jj c). The relative change of the mode-locking frequency with the temperature is 3.65 3 1025y±C. The mode-locking acceptance bandwidth is 675 kHz near the axial-mode frequency spacing at approximately five times the threshold pump power

Interference of Spontaneous Emission of Light from two Solid-State Atomic Ensembles

We report an interference experiment of spontaneous emission of light from two distant solid-state ensembles of atoms that are coherently excited by a short laser pulse. The ensembles are Erbium ions doped into two LiNbO3 crystals with channel waveguides, which are placed in the two arms of a Mach-Zehnder interferometer. The light that is spontaneously emitted after the excitation pulse shows first-order interference. By a strong collective enhancement of the emission, the atoms behave as ideal two-level quantum systems and no which-path information is left in the atomic ensembles after emission of a photon. This results in a high fringe visibility of 95%, which implies that the observed spontaneous emission is highly coherent

Er-Doped Integrated Optical Devices in LiNbO3

The state-of-the-art of Er-doped integrated optical devices in LiNbO3 is reviewed starting with a brief discussion of the technology of Er-indiffusion. This technique yields high-quality waveguides and allows a selective surface doping necessary to develop optical circuits of higher complexity. Doped waveguides have been used as single- and double-pass optical amplifiers for the wavelength range 1530 nm < < 1610 nm. If incorporated in conventional, lossy devices loss-compensating or even amplifying devices can be fabricated. Examples are an electrooptically scanned Ti:Er:LiNbO3 waveguide resonator used as an optical spectrum analyzer and an acoustooptically tunable filter used as a tunable narrowband amplifier. Different types of Ti:Er:LiNbO3 waveguide lasers are presented. Among them are free running Fabry–Perot lasers for six different wavelengths with a conitnuous-wave (CW)-output power up to 63 mW. Tunable lasers could be demonstrated by the intracavity integration of an acoustooptical amplifying wavelength filter yielding a tuning range up to 31 nm. With intracavity electrooptic phase modulation modelocked laser operation has been obtained with pulse repetition frequencies up to 10 GHz; pulses of only a few ps width could be generated.With intracavity amplitude modulation Q-switched laser operation has been achieved leading to the emission of pulses of up to 2.4 W peak power (0.18 J) at 2 kHz repetition frequency. Distributed Bragg reflector (DBR) lasers of emission linewidth 8 kHz have been developed using a dryetched surface grating as one of the mirrors of the laser resonator. Finally, as an example for a monolithic integration of lasers and extracavity devices on the same substrate, a DBR-laser/modulator combination is presented

Optisch parametrische Verstaerkung und Oszillation in Ti-diffundierten LiNbO -Wellenleiterresonatoren

94 refs.SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Efficient Q-Switched Ti:Er:LiNbO3 waveguide lasers

IEE ELECTRONICS LETTER