The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Gunthe Roelkens - One of the best experts on this subject based on the ideXlab platform.
-
silicon photonics traveling wave photodiode with integrated Star Coupler for high linearity mm wave applications
Optics Express, 2018Co-Authors: Laurens Ogae, Kaspe Van Gasse, Thijs Spuesens, Guy Torfs, Joha Auwelinck, Gunthe RoelkensAbstract:Next-generation wireless communication will require increasingly faster data links. To achieve those higher data rates, the shift towards mmWave frequencies and smaller cell sizes will play a major role. Radio-over-Fiber has been proposed as a possible architecture to allow for this shift but is nowadays typically implemented digitally, as CPRI (Common Public Radio Interface). Centralization will be important to keep next-generation architectures cost-effective and therefore shared optical amplification at the central office could be preferable. Unfortunately, limited power handling capabilities of photodetectors still hinder the shift towards centralized optical amplification. Traveling wave photodetectors (TWPDs) have been devised to allow for high-linearity, high-speed opto-electronic conversion. In this paper, an architecture is discussed consisting of such a TWPD implemented on the iSiPP25G silicon photonics platform. A monolithically integrated Star Coupler is added in the design to provide compact power distribution while preserving the high linearity of the TWPD. The traveling wave structure (using 16 photodetectors) has a measured 3 dB bandwidth of 27.5 GHz and a fairly flat S21 up to 50 GHz (less than 1 dB extra loss). Furthermore, the output referred third-order intercept point at 28 GHz, is improved from −1.79 dBm for a single Ge photodiode to 20.98 dBm by adopting the traveling wave design.
Koichi Takiguchi - One of the best experts on this subject based on the ideXlab platform.
-
tunable optical ofdm demultiplexer utilizing slab Star Coupler based optical dft circuit
IEEE Photonics Technology Letters, 2019Co-Authors: Koichi Takiguchi, Yukihiro IkeyamaAbstract:We report on a tunable integrated-optic circuit for demultiplexing optical orthogonal frequency division multiplexing (OFDM) signals with various number of sub-carrier channels. The demultiplexer is composed of tunable optical discrete Fourier transform filter (tunable Couplers, delay lines, and a slab Star Coupler) and optical gates. Various sub-carrier number optical OFDM signals can be demultiplexed by selecting the active delay lines with the tunable Couplers. After explaining the demultiplexer and its operating principle, we show some experimental results including transmittance and bit error rate measurement of demultiplexed sub-carriers from various sub-carrier number optical OFDM signals. $2 \times 10$ Gbit/s to $10 \times 10$ Gbit/s OFDM signals could be successfully demultiplexed.
-
optical orthogonal frequency division multiplexing demultiplexer using slab Star Coupler based optical discrete fourier transform circuit
Optics Letters, 2011Co-Authors: Koichi Takiguchi, Tsutomu Kitoh, Atsushi Mori, Manabu Oguma, Hiroshi TakahashiAbstract:We demonstrate an optical orthogonal frequency division multiplexing (OFDM) demultiplexer with an optical discrete Fourier transform circuit fabricated using silica planar lightwave circuit technology. This compact device can process an arbitrary number of subcarriers. The operation of a ten-channel device is demonstrated by demultiplexing a 100 Gbit/s (10 subcarrier×10 Gbits/s) OFDM signal. We also discuss a main factor affecting characteristics degradation of the device.
-
integrated optic ofdm demultiplexer using slab Star Coupler based optical dft circuit
European Conference on Optical Communication, 2010Co-Authors: Koichi Takiguchi, Tsutomu Kitoh, Atsushi Mori, Manabu Oguma, Hiroshi TakahashiAbstract:We present a novel optical OFDM demultiplexer with a silica-PLC-based optical DFT circuit. This compact device can process an arbitrary number of subcarriers. The operation of a ten-channel device is demonstrated by demultiplexing a 100-Gbit/s (10-subcarrier × 10-Gbit/s) OFDM signal.
Libo Yua - One of the best experts on this subject based on the ideXlab platform.
-
schemes of a fiber optic multiplexing sensor array based on a 3 3 Star Coupler
Optics Letters, 2005Co-Authors: Libo Yua, Ju YangAbstract:A Michelson-based fiber-optic low-coherence interferometric quasi-distributed sensing system permitting absolute length measurement in a sensor array is proposed. The main part of the sensing system is a fiber-optic 3×3 Star Coupler. The architecture of fiber-optic sensors can be easily realized as a linear sensor array, twin sensor arrays, or a loop sensor array. The proposed sensing scheme will be useful for the measurement of strain distribution. An important application could be deformation sensing in smart structures. A six-sensor array is demonstrated experimentally.
-
distributed fiber optic white light interferometric strain sensors array with a 3 3 Star Coupler
Advanced Sensor Systems and Applications II, 2005Co-Authors: Libo Yua, Ju YangAbstract:A Michelson based fiber optic low-coherence interferometric quasi-distributed sensing system permitting absolute length measurement in the sensors array is proposed. The main part of the sensing system is a fiber optic 3x3 Star Coupler. The architecture of the fiber optic sensors can be easy realized as a linear sensor array, twin sensor arrays or a loop sensor array. The proposed sensing scheme will be useful for the measurement of strain distribution. An important application could be deformation sensing in smart structures. Experimentally, a 6 sensors array has been demonstrated.
-
1 x n Star Coupler as a distributed fiber optic strain sensor in a white light interferometer
Applied Optics, 1998Co-Authors: Libo Yua, Limi ZhouAbstract:A novel technique of using a 1 × N Star fiber optic Coupler as a distributed strain sensor in a white-light interferometer to measure the distribution of strain is presented. The measuring principle and 1 × 4 Star Coupler with four fiber optic strain sensors are demonstrated. The experiment is performed with four sensors attached to a combination plastic specimen.
Laurens Ogae - One of the best experts on this subject based on the ideXlab platform.
-
silicon photonics traveling wave photodiode with integrated Star Coupler for high linearity mm wave applications
Optics Express, 2018Co-Authors: Laurens Ogae, Kaspe Van Gasse, Thijs Spuesens, Guy Torfs, Joha Auwelinck, Gunthe RoelkensAbstract:Next-generation wireless communication will require increasingly faster data links. To achieve those higher data rates, the shift towards mmWave frequencies and smaller cell sizes will play a major role. Radio-over-Fiber has been proposed as a possible architecture to allow for this shift but is nowadays typically implemented digitally, as CPRI (Common Public Radio Interface). Centralization will be important to keep next-generation architectures cost-effective and therefore shared optical amplification at the central office could be preferable. Unfortunately, limited power handling capabilities of photodetectors still hinder the shift towards centralized optical amplification. Traveling wave photodetectors (TWPDs) have been devised to allow for high-linearity, high-speed opto-electronic conversion. In this paper, an architecture is discussed consisting of such a TWPD implemented on the iSiPP25G silicon photonics platform. A monolithically integrated Star Coupler is added in the design to provide compact power distribution while preserving the high linearity of the TWPD. The traveling wave structure (using 16 photodetectors) has a measured 3 dB bandwidth of 27.5 GHz and a fairly flat S21 up to 50 GHz (less than 1 dB extra loss). Furthermore, the output referred third-order intercept point at 28 GHz, is improved from −1.79 dBm for a single Ge photodiode to 20.98 dBm by adopting the traveling wave design.
Yukihiro Ikeyama - One of the best experts on this subject based on the ideXlab platform.
-
tunable optical ofdm demultiplexer utilizing slab Star Coupler based optical dft circuit
IEEE Photonics Technology Letters, 2019Co-Authors: Koichi Takiguchi, Yukihiro IkeyamaAbstract:We report on a tunable integrated-optic circuit for demultiplexing optical orthogonal frequency division multiplexing (OFDM) signals with various number of sub-carrier channels. The demultiplexer is composed of tunable optical discrete Fourier transform filter (tunable Couplers, delay lines, and a slab Star Coupler) and optical gates. Various sub-carrier number optical OFDM signals can be demultiplexed by selecting the active delay lines with the tunable Couplers. After explaining the demultiplexer and its operating principle, we show some experimental results including transmittance and bit error rate measurement of demultiplexed sub-carriers from various sub-carrier number optical OFDM signals. $2 \times 10$ Gbit/s to $10 \times 10$ Gbit/s OFDM signals could be successfully demultiplexed.
