[show abstract][hide abstract] ABSTRACT: The prospect of silicon photonics is particularly promising: the fabrication is mostly compatible with standard CMOS technology and it will offer tremendous advantages over traditional optical communication solutions with respect to size, cost and power. There has been a significant activity in the development of photonic circuits having a density approaching that of modern electronic circuits for future chip-to-chip or on- chip optical interconnects. Therefore, an ultrasmall footprint of integrated optical components is of pivotal importance.
Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009. European Conference on; 07/2009
[show abstract][hide abstract] ABSTRACT: We combined high resolution laser spectroscopy and microscopy to identify individual molecules in two independent microscopes. Then the Stark effect was exploited to tune the transition frequencies of the molecules and thus obtain indistinguishable single photons.
Lasers and Electro-Optics, 2008 and 2008 Conference on Quantum Electronics and Laser Science. CLEO/QELS 2008. Conference on; 06/2008
[show abstract][hide abstract] ABSTRACT: Light-matter interaction on the level of single emitters and single photons has attracted significant scientific interest in recent years. Of particular interest is strong coupling of single emitters in solid state systems and its application to quantum information processing. Due to the enormous progress in semiconductor technology it has become feasible to demonstrate strong coupling of single quantum dots in high-Q microcavity systems. Although it has been argued in these studies that it is very unlikely that several degenerated quantum dots contributed to the observed Rabi-splitting, it was not verified that the system had one and only one emitter. In this work we present proof that the emission from a strongly-coupled QD- microcavity system is dominated by a single quantum emitter.
Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference. CLEOE-IQEC 2007. European Conference on; 07/2007
[show abstract][hide abstract] ABSTRACT: Induced coupling between two counterpropagating modes in a microsphere resonator is studied under controllable conditions. A transition from weak to strong coupling is observed, similar to a coupled system composed of a single atom and a single cavity mode.
[show abstract][hide abstract] ABSTRACT: This study investigates a system which provides an analogy between cavity quantum electrodynamic (CQED) effects (dipole and cavity) and the modal coupling of high-Q modes in an optical microresonator induced by a Rayleigh scatterer. This is accomplished by utilizing a scanning near field optical microscope tip as a controllable Rayleigh scatterer. Analysis in terms of CQED provides a better understanding of the large mode splitting previously observed in microresonators.
[show abstract][hide abstract] ABSTRACT: We present an experiment where a single nanoparticle can be coupled under controlled conditions to the high-Q modes of a microsphere resonator. These modes are then used to mediate an energy transfer between two nanoparticles.
Quantum Electronics and Laser Science Conference, 2005. QELS '05; 06/2005
[show abstract][hide abstract] ABSTRACT: We present measurements of the second-order coherence function on emission from single GaN quantum dots. A large degree of photon antibunching is observed, demonstrating single-photon source operating at a record-short wavelength of 357 nm.
Quantum Electronics and Laser Science Conference, 2005. QELS '05; 06/2005
[show abstract][hide abstract] ABSTRACT: We present measurements of the second-order coherence function on emission from single GaN quantum dots. In some cases a large degree of photon antibunching is observed, demonstrating isolation of a single quantum system. For a selected quantum dot, we study the dependence of photon antibunching on excitation power and temperature. Using pulsed excitation, we demonstrate an ultraviolet triggered single-photon source operating at a wavelength of 358 nm. Comment: 3 pages, 4 figures
[show abstract][hide abstract] ABSTRACT: We use optical near-field techniques to characterize and manipulate high-Q whispering-gallery modes of silica microspheres and to couple them to a single nano-emitter. Furthermore, we study the coupling of two nano-emitters via the whispering-gallery modes and discuss future plans.
Biophotonics/Optical Interconnects and VLSI Photonics/WBM Microcavities, 2004 Digest of the LEOS Summer Topical Meetings; 07/2004
[show abstract][hide abstract] ABSTRACT: The paper briefly describes the performed experiment, in which the coupling of a single 500 nm dye-doped bead and semiconductor nanocrystals to high-Q silica microsphere resonators is realized, as well as the detection of the fluorescence via a well defined and controllable output port. A homemade confocal laser scanning microscope was used for selecting and addressing single nanoparticles on the microsphere surface. At the same time a prism served as an outcoupling port for the fluorescence coupled to the whispering gallery modes (WGMs). The experimental setup allowed to control the coupling and to determine the Q-factor of the WGMs in the microsphere.
[show abstract][hide abstract] ABSTRACT: Summary form only given. In our novel experimental set-up, an active nanoparticle is attached to the end of a fiber tip. In order to achieve coupling, the tapered fiber tip is placed close to the surface of a microsphere resonator using the shear-force mechanism. In this way, light emitted from the nanoparticle couples to the cavity, when the particle is optically pumped via the fiber. In a first experiment, a stabilized diode laser was frequency-tuned across a single whispering-gallery mode. The light scattered into a bare fiber tip was recorded while scanning 10 μm perpendicular to the equator of the sphere with a constant tip-sphere separation of approx. 10 nm. In another experiment, we placed a larger tapered and cleaved fiber tip (front diameter 13.5 μm) in an intensity maximum of a particular high-Q whispering-gallery mode.
[show abstract][hide abstract] ABSTRACT: Summary form only given. Optical microsphere resonators are attractive systems for both fundamental physics research in the field of cavity quantum electrodynamics and for the use in optoelectronic devices. So-called whispering-gallery modes of such cavities feature extreme photonic confinement with very small mode volume and a very high quality (or Q-) factor. Here, we report on a new experiment where we couple a single mode fiber tip to individual modes of a microsphere resonator. In order to acheive coupling; the tapered fiber tip is placed close to the sphere surface and light from the evanescent field on the sphere surface scatters into the fiber.
[show abstract][hide abstract] ABSTRACT: ne (DBA IT) molecules embedded in tetradecane matrices at cryogenic temperatures below 2K. Narrow-band photons (linewidth 20 MHz) were generated by pumping the source molecule into its first vibrational level of the electronic excited state and extracting the emission on the zero-phonon-zero -vibrational (ZP-OO) transition between the electronic excited and ground states. The emitted single photons were characterized by recording the second-order correlation function of the emission. The photons were then coupled into a single mode fiber and were focused onto the target molecule using a solid-immersion lens system. To scan the frequency of the emitted photons through the resonance of the target molecule, we exploited the Stark effect. We applied a variable electric field to microelectrodes embedded on the sample containing the source molecule [4). To detect the excitation of the target molecule, we monitored its effect on the intensity of the excitation beam in a reflection geometry. The resulting signal was recorded at a rate of 2000 photons per second. We report on the substantial attenuation of the single-photon beam by more than 2% after interaction with the target molecule [3). We discuss the details of our experimental system and its potential for efficient coupling of single photons and single emitters without the need for microcavities.
[show abstract][hide abstract] ABSTRACT: Lasing properties of an ultra-low threshold microsphere Raman laser are studied with a near-field probe. The probe is modelled as a Rayleigh scatterer and its influence on the lasing process is investigated.