Related papers: Developing arrayed waveguide grating spectrographs…
It has been seen recently that when probing a nanoscale object to determine, for example, size or position via light scattering, significant advantage in measurement precision can be gained from exploiting phase singularities in a…
The demonstration of an optical fiber based probe for efficiently exciting the waveguide modes of high-index contrast planar photonic crystal (PC) slabs is presented. Utilizing the dispersion of the PC, fiber taper waveguides formed from…
A standard multimode optical fiber can be used as a general purpose spectrometer after calibrating the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A transmission matrix was used to…
We theoretically investigate several types of plasmonic slot waveguides for enhancing the measured signal in Raman spectroscopy, which is a consequence of electric field and Purcell factor enhancements, as well as an increase in…
Arrayed Waveguide Gratings (AWGs) are widely used photonic components for splitting and combining different wavelengths of light. They play a key role in wavelength division multiplexing (WDM) systems by enabling efficient routing of…
We experimentally demonstrate a broadband, fabrication tolerant, CMOS compatible compact silicon waveguide taper (34.2 um) in silicon-on-insulator wire waveguides. The taper works on multi-mode interference along the length of the taper. A…
Adiabatic waveguide taper and on-chip wavelength demultiplexer are the key components of photonic integrated circuits. However, these two kinds of devices which designed by traditional semi-analytic methods or brute-force search methods…
We present the design and characterization of waveguide grating devices that couple visible-wavelength light at $\lambda=674$ nm from single-mode, high index-contrast dielectric waveguides to free-space beams forming micron-scale…
A general-purpose all-fiber spectrometer is demonstrated to overcome the trade-off between spectral resolution and bandwidth. By integrating a wavelength division multiplexer with five multimode optical fibers, we have achieved 100 nm…
In astronomical spectroscopy, optical fibres are abundantly used for multiplexing and decoupling the spectrograph from the telescope to provide stability in a controlled environment. However, fibres are less than perfect optical components…
We propose a new technique, the use of FBGs (fiber Bragg gratings), for accurate, easy and low cost wavelength calibration of GAIA, RAVE and follow-ups spectra at local Observatories. FBGs mark the spectra with absorption lines, freely…
Efficient fiber-to-chip couplers for multi-port access to photonic integrated circuits are paramount for a broad class of applications, ranging, e.g., from telecommunication to photonic computing and quantum technologies. While…
In ground-based astronomy, the ability to couple light into single-mode fibers (SMFs) is limited by atmospheric turbulence, which prohibits the use of many astrophotonic instruments. We propose a silicon-on-insulator photonic chip capable…
We demonstrate an optical phased-array (OPA) equipped with a 3D-printed facet-attached element for shaping and deflection of the emitted beam. The beam shaper combines freeform refractive surfaces with total-internal-reflection (TIR)…
We present results from the first on-sky demonstration of a prototype astronomical integrated photonic spectrograph (IPS) using the Anglo-Australian Telescope near-infrared imaging spectrometer (IRIS2) at Siding Spring Observatory to…
We demonstrate adiabatically tapered fibers terminating in sub-micron tips that are clad with a higher-index material for coupling to an on-chip waveguide. This cladding enables coupling to a high-index waveguide without losing light to the…
We report on the experimental demonstration of the broadband "trapped rainbow" in the visible range using arrays of adiabatically tapered optical nano waveguides. Being a distinct case of the slow light phenomenon, the trapped rainbow…
We report on the development of a compact (volume $\approx$ 100\:cm$^3$), multimode diffraction-limited Raman spectrograph and probe designed to be compact as possible. The spectrograph uses `off the shelf' optics, a custom 3D-printed…
Many focal-reducer spectrographs, currently available at state-of-the art telescopes facilities, would benefit from a simple refurbishing that could increase both the resolution and spectral range in order to cope with the progressively…
Achieving large bandwidth at strong mode conversion strengths is a central problem in few-mode optical waveguides. The most uncomplicated modification of a standard mode-converting grating is to incorporate a single extra gap. Such simple…