http://www.researchonline.mq.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:25379 We present a canonical quantization of macroscopic electrodynamics. The results apply to inhomogeneous media with a broad class of linear magneto-electric responses which are consistent with the Kramers-Kronig and Onsager relations. Through its ability to accommodate strong dispersion and loss, our theory provides a rigorous foundation for the study of quantum optical processes in structures incorporating metamaterials, provided these may be modeled as magneto-electric media. Here we present our results in a mode expansion picture with a view to applications in guided wave and cavity quantum optics. The classical limit of our theory provides a rigorous foundation for the study of light propagation in highly dispersive and lossy negative index materials. 2013-05-09T09:36:55.204Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:25334 We demonstrate three and four input multiports in a three dimensional glass platform, fabricated using the femtosecond laser directwrite technique. Hong-Ou-Mandel (HOM) interference is observed and a full quantum characterization is performed, obtaining two photon correlation matrices for all combinations of input and output ports. For the 3-port case, the quantum visibilities are accurately predicted solely from measurement of the classical coupling ratios. 2013-04-26T05:20:14.725Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:25335 We characterize a three dimensional three port beamsplitter device using two photons, the first example of this device in integrated photonics. We observe a Hong-Ou-Mandel dip between output ports showing quantum interference and construct a correlation matrix. 2013-04-26T05:20:12.260Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:23306 We theoretically analyze the dynamical evolution of photonic quantum walks on Möbius strips and other exotic structures in three-dimensional integrated photonics. Our flexible design allows discrete observations of continuous-time quantum walks of photons in a variety of waveguide arrays. Furthermore, our design allows one to inject photons during the evolution, allowing the possibility of interacting with the photons as they are "walking." We find that nontrivial array topologies introduce time-dependent symmetries of the two-photon correlations. These properties allow a large degree of control for quantum state engineering of multimode entangled states in these devices. 2012-12-10T01:50:35.179Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:20317 We investigate the intracellular uptake of 7.3. nm, 21.2. nm and 31.3. nm average size pure colloidal gold nanoparticles synthesized using femtosecond laser ablation technique in pure water. Dark-field imaging, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) was used to assess the uptake of these pure gold nanoparticles in the pancreatic tumor cell line. We show that these ligand-free gold nanoparticles are non-toxic to these cells. The nanoparticles and cell images indicated that unmodified gold nanoparticles interacted with the cells, despite negative surface charge on both the cells and the nanoparticles. We also demonstrate that the uptake of the gold nanoparticles is size-dependent. 2012-07-11T11:23:37.999Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19360 We are using a femtosecond laser to inscribe a series of integrated photonic lanterns that have a range of refractive index contrasts and geometry parameters in order to determine the ideal format for optimising the single-mode to multimode transition efficiency. 2012-06-27T10:19:22.488Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:20093 The intensity pulsations of a cw 1030 nm Yb:Phosphate monolithic waveguide laser with distributed feedback are described. We show that the pulsations could result from the coupling of the two orthogonal polarization modes through the two photon process of cooperative luminescence. The predictions of the presented theoretical model agree well with the observed behaviour. 2012-06-27T10:11:44.097Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:20097 A faster method of simulating 2D slabs, both metallic and dielectric, with cylindrical inclusions is proposed. The method is applicable to photonic crystal defect-row waveguides and extraordinary transmssion through metallic films, capable of producing both in-plane dispersion relations and transmission spectra. 2012-06-27T10:11:24.101Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:20108 We study the radiation dynamics of an electric line current source in a homogeneous, magneto-dielectric cylinder. We find that radiation by the source is most enhanced by maximizing the magnetic response of the cylinder. 2012-06-27T10:10:34.661Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19611 Integrated photonics is a promising technology platform for use in space based environments. In this paper we explore the effects of space-like conditions, including temperature, pressure, and exposure to x-rays and gamma rays, on waveguides fabricated in glass by the femtosecond laser direct write technique. 2012-06-05T08:21:08.818Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19270 For the first time we explore femtosecond laser writing of waveguides in magneto-optical glasses using athermal writing inscription. Single mode guidance at visible is demonstrated and opportunities for optional isolators will be reported. 2012-05-23T21:35:41.706Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19328 We present coupled-mode-theory modeling of apodized fiber Bragg gratings inscribed using a point-by-point technique. We show that the local detuning in these gratings is almost constant, due to the morphology of the femtosecond laser-inscribed structures. 2012-05-23T21:35:05.594Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19330 Photonic devices for quantum logic will require tight control over their birefringent properties. In this study we seek to better understand the influence of birefringence in coupled waveguide systems and establish boundary conditions for future quantum photonic systems. 2012-05-23T21:34:55.073Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19361 We demonstrate direct laser written low loss waveguides in bismuth germanate for sensing applications in high energy physics. We discuss the suitability of waveguide arrays in this material for spatial resolved radiation detection. 2012-05-23T21:32:42.139Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19367 Integrated photonics offer numerous advantages for developing high dynamic range stellar interferometers for exoplanetary science. We report on the results from the first successful on-telescope tests of an integrated photonic pupil remapping interferometer. 2012-05-23T21:32:15.987Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19366 The invention of the Chirped Pulse Oscillator (CPO) concept enabled the generation of sub-50 fs laser pulses at MHz repetition rates with an energy approaching the muJ-level directly out of an oscillator. Such laser sources close the gap between low-energy oscillators on the one hand and complex amplifier systems on the other hand and are perfectly suited for high-speed fabrication of Photonic devices with feature sizes down to the sub-micron regime. In this paper we review the latest advances in CPO development and report on our capabilities to utilize those sources to fabricate integrated devices in a variety of passive as well as active materials. 2012-05-23T21:32:13.382Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19370 We report a dual-wavelength (DW) distributed feedback (DFB) waveguide laser based on a symmetric periodically sampled grating fabricated in Yb-doped phosphate glass, using the femtosecond laser direct-write technique. The experimental results show that the peak spacing must be larger than 10 nm for stable operation. For improvement of the lasing performance, an asymmetric sampled grating structure is proposed such that a DW-DFB waveguide laser with 40 pm peak spacing is possible. 2012-05-23T21:31:56.175Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19371 We study the radiation dynamics of a dipole inside a discrete invisibility cloak. The dynamics differ drastically from the case of an ideal, continuous cloak, with the cloak sometimes enhancing the visibility of the source. 2012-05-23T21:31:56.130Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19236 The femtosecond laser direct write technique enables the fabrication of integrated three dimensional miniaturised optical components in various transparent dielectric media by translating those samples with a computer controlled stage with respect to a tightly focused laser beam. Nonlinear absorption processes can lead to a pathway of local permanent index change inside the material. In this paper we review our work in glasses doped with active ions. Integrated waveguide amplifiers working in the wavelength range between 1-3 micron have been realised by inscribing low-loss optical waveguides in phosphate, borosilicate or fluoride glasses doped with rare-earth ions like erbium, ytterbium, holmium or thulium. By incorporating wavelength-selective feedback elements like fibre- or waveguide Bragg gratings or distributed feedback structures, integrated chip lasers have been fabricated. 2012-05-21T18:46:08.219Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:19059 We demonstrate the first 1550 nm correlated photon-pair source in a highly nonlinear integrated glass waveguide. A pair coincidence rate of 80s was achieved with the correlation ratio limited by Raman effects. 2012-05-08T16:21:28.399Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:18295 The use of a scanned femtosecond laser focus to create opti cal waveguide devices is an established and powerful technique [1] with applications in sensing and quantum information [2]. Using a sub-surface focussed femtosecond laser, a dielectric material can be modified at a highly localised point without surrounding material modification. By controlling the laser-photonic material interactions and fabrication parameters [3-5], a permanent change in the refractive index of the material can be achieved. Not only can this direct-write technique be carried out rapidly, it is readily compatible with existing fibre systems, it does not require a lithographic mask and it can be conducted in a regular laboratory environment with the minimum of sample preparation. 2012-03-26T16:01:20.683Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:18297 Bismuth germanate (Bi4Ge3O12) BGO is an interesting material for a wide range of optical sensing applications. The high electro-optic coefficient makes BGO suitable for high voltage and field sensing applications with high accuracy [1]. Further, single crystals are used as scintillator in combination with photo multiplier tubes or avalanche photodiodes. Arrays of these scintillator devices are used for positron emission tomography (PET), a common medical imaging system. However, the size of crystals arrays limits the resolution and makes the system expensive. To fully enhance the potential of this material in integrated optical circuits the fabrication of buried waveguides by ion implantation has been discussed [2]. The highly flexible technique of optical waveguide writing by tightly focused femtosecond laser pulses is a promising alternative; however, the inscription of positive index changes in crystals is difficult due to the crystal lattice. 2012-03-26T16:01:16.434Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:18267 The short to mid-infrared spectral regions are key to many applications that require low-cost and spectrally selective sources of coherent radiation. To name a few applications, they range from trace gas spectroscopy to process control, environmental safety monitoring, and testing of infrared countermeasure systems. 2012-03-22T08:50:21.499Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:18158 Heavy-metal fluoride glass is well known for its high infrared transparency, especially in its most common composition ZrF4-BaF 2-LaF3-AlF3-NaF (ZBLAN), which makes it an attractive host for mid-infrared emitting rare-earth ions. The mid-infrared wavelength region is of particular interest for many applications like molecular spectroscopy, process monitoring and infrared countermeasures, which demand a robust, simple and cheap laser source. We recently demonstrated a Tm 3+:ZBLAN waveguide laser emitting at 1.9 m with a slope efficiency approaching 40% [1]. The devi ce is based on novel laser-written depressed cladding waveguides with butt-coupled bulk mirrors. However to obtain a highly integrated and robust laser system a different approach to providing the resonator feedback must be applied. A significant innovation would be the integration of Bragg-gratings into the waveguide in the form of distributed feedback (DFB) or distributed Bragg reflector (DBR) structures, thereby resulting in a monolithic device with narrow line width output [2]. 2012-03-19T11:30:53.819Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:18160 Waveguides written in active glasses and that incorporate Bragg gratings form the basis of a stable, monolithic waveguide laser platform fabricated at Macquarie University. Previously we have demonstrated single wavelength structures based on ytterbium doped phosphate glasses; these allow laser operation near 1030 nm and with output powers of several hundred milliwatts [1]. The distributed-feedback laser devices can be unidirectionally or double-end pumped and the balance of laser power emitted from the facets is controlled by the position of a phase shift in the grating structure. 2012-03-19T11:30:46.459Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:15870 We present a narrow-linewidth, linearly polarized neodymium-doped fiber laser that incorporates a point-by-point Bragg grating inscribed into the core of a single-polarization all-solid photonic bandgap fiber. The Bragg grating was written within a single-polarization wavelength band of the fiber; thus, the Bragg reflection was polarized. This all-fiber laser produced 7.2W, linearly polarized output with 25pm FWHM and 19.6 dB polarization extinction ratio. 2011-11-09T03:10:36.297Z ]]>