19x10-GHz electro-optic ultra-flat frequency comb generation only using single conventional Mach-Zehnder modulator
ABSTRACT We demonstrated ultra-flat optical frequency comb generation only using a set of conventional Mach-Zehnder modulator asymmetrically dual-driven by large-amplitude sinusoidal signals with different amplitudes. 19-channel 10-GHz-spaced frequency comb with ≪4.6-dB spectral ripple was experimentally generated.
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ABSTRACT: We report that completely athermal design of a slotted silicon waveguide is possible by combining the negative thermo-optic (TO) coefficient of, for example, polymethyl methacrylate (PMMA) with the positive TO coefficient of silicon. When used in a microring resonator structure, the filled overcladding slotted waveguide and the unfilled (air-filled) overcladding slotted waveguide can both achieve athermal characteristics. Simulations indicate a wide range of realizations with proper design parameters of the slotted waveguides, namely, the silicon strip and slot widths. Preliminary experimental results on fabricated devices demonstrate that the temperature dependence is reduced from 91 pm/°C for a regular microring resonator to 52 pm/°C for the PMMA-clad microring resonator. Completely athermal realization is expectable in similar devices with improved fabrication techniques. For the external optical source, we demonstrate a stable 3.5 THz wide (175 modes×20 GHz) optical comb source with nearly flat spectral phase. Adjustable mode spacing and wavelength tunability across the C-band are maintained so that comb lines can be matched to the specified wavelength grid of the computing system. With such schemes, temperature controls of individual optical components in the optically interconnected computing chips become unnecessary, greatly reducing the complexity of the computing system.Applied Physics A 01/2009; 94:1101-1109. · 1.69 Impact Factor
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ABSTRACT: We demonstrate an ultra-wideband light source using multi-wavelength single-sideband modulation (SSB) frequency sweep technique, aiming at optical coherence tomography (OCT). The light source consists of an optical SSB frequency sweeper with an optical frequency comb generator cascaded with a multi-wavelength laser. Ultra-wideband signal was generated by sweeping frequency of each components of an optical multi-wavelength light source. The proposed system can achieve much faster and more precise spectrum measurement than the conventional OCT system.Microwave Photonics, 2007 IEEE International Topical Meeting on; 11/2007
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ABSTRACT: A wavelength tunable optical comb is generated based on the gain-switching of an externally seeded Fabry-Pérot laser diode. The comb consists of about eight clearly resolved 10 GHz coherent sidebands within 3 dB spectral envelope peak and is tunable over the entire C-band (1530 to 1570 nm). The optical linewidth of the individual comb tones is measured to be lower than 100 kHz, and the RIN of the individually filtered comb tones (<-120 dB/Hz) is shown to be comparable to the entire unfiltered comb (<-135 dB/Hz). Besides, expansion of the tunable gain switched comb is achieved with the aid of an optical phase modulator, resulting in near doubling of the number of comb tones.Optics Express 12/2011; 19(26):B415-20. · 3.55 Impact Factor