Abstract:
Using a transformer coupled plasma reactor, it is possible to achieve continuous production of plasma which decomposes precursors containing silicon in order to produce pure silicon powder. The pure silicon powder is then gathered, treated and used to produce ingots of silicon for use in photovoltaics or semiconductors.
Abstract:
The present document relates to the field of optical access networks. In particular, the present document relates to an optical transmitter, in particular (but not exclusively) for a WDM (Wavelength Division Multiplexing) passive optical network, and to a WDM PON comprising such an optical transmitter. An optical transmitter arrangement (7) is described. The arrangement (7) comprises a first mirror (41) and a second mirror (64) at a first end and a second end of a cavity, respectively; an optical amplifier (63) configured to amplify light polarized in a first polarization plane; wherein the optical amplifier (63) is positioned within the cavity upstream the first mirror (64); an optical waveguide (5-2) configured to transmit light from the optical amplifier (63) to the second mirror (41) and vice versa; a first non-reciprocal polarization rotator (82) positioned within the cavity upstream of the optical amplifier (63) and downstream of the optical waveguide (5-2); and a second non-reciprocal polarization rotator (81) positioned within the cavity upstream of the optical waveguide (5-2) and downstream of the first mirror (41); wherein the first (82) and second (81) non-reciprocal polarization rotators are configured to rotate the polarization of the light such that light which re-enters the optical amplifier (63) after having been reflected by the second mirror (41) is polarized in the first polarization plane.
Abstract:
Methods, systems, and apparatus, for an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.
Abstract:
Tunable add/drop optical device for injecting or extracting (add/drop) at least a selected optical channel or carrier wavelength in or from a set of multiplexed channels or carriers of different wavelengths comprising a plurality of directional couplers (AD1... AD6) and a plurality of phase-shift stages (SF1...SF5) alternately connected in cascade, wherein each phase-shift stage defines a certain optical path length difference ( DELTA L1... DELTA L5) between two distinct optical paths of the stage. The tuning is performed modifying the refraction index of one path of said phase shift stages by means of Joule effect heating strips (L1... L5) or by means of metallic field plates adapted to receive a signal suitable to modify the electric field intensity. The first two phase-shift stages of said plurality of phase-shift stages have differences of length of optical paths different from each other and in a preestablished ratio while the remaining phase-shift stages have differences of length of optical paths identical. It is thus possible to provide a device having an exceptionally flat cross response characteristic, substantially free of ripple due to an inevitable truncation of the Fourier expansion series.
Abstract:
Using a transformer coupled plasma reactor, it is possible to achieve continuous production of plasma which decomposes precursors containing silicon in order to produce pure silicon powder. The pure silicon powder is then gathered, treated and used to produce ingots of silicon for use in photovoltaics or semiconductors.