Rolland Hierle

Simple interferometric technique for generation of a radially polarized light beam

We present a theoretical and experimental investigation of an interferometric technique for converting a linearly polarized Gaussian beam into a radially polarized doughnut beam. The experimental setup accomplishes the coherent summation of two orthogonally polarized TEM01 and TEM10 beams that are obtained from the transformation of a TEM00 beam by use of a simple binary diffractive optical element. We have shown that the degree of radial polarization is maximum at a given distance from the interferometer output port that depends on the diameter of the incident beam at the interferometer input port.

Demonstration of net gain at 1550nm in an erbium-doped polymersingle mode rib waveguide

A polymer-based waveguide optical amplifier doped with Er3+ ions has been modeled, fabricated, and characterized. Propagation losses have been measured using both cutback and Fabry-Perot methods, resulting in similar, reasonable loss values that do not exceed 1.31dBcm−1 at 1540nm. By accounting for overall propagation loss, a net gain of 1.34dB at 1540nm is demonstrated for a 1.6cm long single mode waveguide amplifier.

Quasiphase matched second-harmonic generation from periodic optical randomization of poled polymer channel waveguides

We present experimental evidence of quasiphase-matched second harmonic generation in a polymer channel waveguide consisting of disperse red one (DR1) grafted to a poly(methylmethacrylate) (PMMA) main chain polymer at 30% molecular weight concentration. The ability of DR1 to photoisomerize is used to define a periodic segment of linear and nonlinear domains along the waveguide by photodepoling through a photolithographic mask of 10 μm periodicity, following quasiphase-matching requirements. A broad spectral scan between 1450 and 1800 nm evidences a peaked enhancement of second harmonic generation at 1536 nm, with experimental efficiency of 0.023% W−1, further compared to theoretical values. Wavelength dispersion of the quasiphase matched second harmonic peak as well as the penetration depth of the photodepoling beam in DR1 PMMA are also discussed.

Electrooptic probe based on an organic microcavity

We present the concept of an electrooptic (EO) probe based on a thin organic layer of DR1-PMMA embedded in a high finesse Fabry-Pe/spl acute/rot cavity with optimal orientation of the DR1 molecules, parallel to the faces of the microcavity. This optimal orientation is obtained through a lateral poling method and an r/sub 33/ value of 2.5 pm/V is reached for a 16-/spl mu/m-thick DR1-PMMA layer. This EO probe shows a high sensitivity of 2 V/spl middot/cm/sup -1//spl middot/Hz/sup -1/2/.

New electro-optic modulator based on polymer waveguide and loop structure

Photonics devices based on polymer optical waveguides are widely studied now and some commercial announcements have already been published. Nevertheless they are not been followed by really available products and it is still necessary to improve such kind of devices. The aim of this paper is to present a new structure for a polymer electro-optic modulator. The electro-optic polymer material is PMMA-DR1. This electro-optic polymer is well known by its high frequency bandwidth of modulation and its functional robustness. Nevertheless, its half-wave voltage remains relatively high, that is why a new configuration is proposed decreasing the half-wave voltage. The new device, which is fully described, is based on the classical Mach-Zehnder optical modulator structure, to which a completely new loop structure is added. Thus the optical waveguides are designed in order to increase the active length and so reducing the half-wave voltage. Otherwise the device is designed for a complete planar realization. The RF strip lines are also designed according to the loop structure with 50Ω characteristic impedance. A device has been realized and its optical are checked at 1.55μm wavelength. Electronic characteristics should be determined by the way of spectrum and network analyzers at frequencies up to 2GHz. All the measurements should show the feasibility and efficiency of the new structure.

Demonstration of net gain at 1540 nm in an erbium-doped polymer single mode rib waveguide

A polymer-based waveguide amplifier doped with Er3+ ions has been modelized, elaborated and characterized. An internal net gain of 1.34 dB at 1540 nm is demonstrated for a single-mode waveguide of 1.6 cm length.

Design of a new photomixer based on electro-optic polymer

A new photomixer based on the nonlinear behavior of an electro-optic polymer material is proposed here. The microwave frequency is generated by mixing two optical signal waves propagating simultaneously inside an optical waveguide made of the crosslinked PMMA-DR1 electro-optic copolymer; the cladding layers are made of NOA material and the microwave signal is collected on a microstrip line. By matching the velocities of the microwave signal and of the optical signals it is possible to create constructive mixing in a traveling-wave configuration at more than 60 GHz. If one of the optical waves is modulated by an informative signal, the microwave signal will infer the modulation

Organic Fabry-Perot micro-cavity for electro-optic sampling by amplitude modulation

We present herein a original concept of electro-optic (EO) probe for high frequency electric field measurements. This sensors is based on a thin organic layer of DR1-PMMA embedded in a high finesse Fabry-Perot cavity. The optimal orientation of DRl molecules, parallel to the face of the micro-cavity, has been obtained thanks to a lateral poling method. A r33 of 2.5 pm/V has been reached for a 16 μm thick polymer layer. The final probe exhibits high sensitivity of 2V.cm-1.Hz-1/2.

Advances in polymer based photonics technology: microlasers, electrooptic devices, new concepts

The emergence of molecular photonics as a new domain of research at the cross-road of physics, chemistry and device engineering is being triggered by the increasing demands of broadband telecommunication systems which start to challenge the fundamental limits of current inorganic semiconductor based technologies. Increasing to 100 GHz and beyond the bandwidth acceptance of optoelectronic devices, such as modulators and switches, or down-scaling device dimensions into the new frontier of quantum physics have become scientific as well as industrially relevant targets, unlikely to be met by unimaginative extrapolation of current avenues. Facing this formidable challenge, the so-far relatively untapped wealth of molecular structures, and the targeted exploitation of their functional as well as structural flexibility throughout consistent molecular, material and device engineering steps, open-up thoroughly renewed horizons. An important asset is the complementarity and technological compatibility of polymer and inorganic semiconductor structures providing the possibility of smooth and economically viable transitions towards hybrid organic-inorganic technological solutions. Major current and foreseeable impacts appear to be in the realm of nonlinear optics (harmonic generation and carrier frequency shifting, routing, electrooptic modulation and switching, pulse shaping and synchronization, nonlinear refraction) and microlasers which will be exemplified by a selection of recent and ongoing developments in our laboratory at different macroscopic, microscopic and nanoscopic scales.