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Optical Current Sensor
Optical Current Sensor
Integrated Optic Current Sensors (IOCS) are next-generation optical devices designed for power monitoring and leakage prevention in electrical grid networks. These sensors offer significant advantages over traditional electrical sensors, including EMI-free operation, a linear response over a wide frequency bandwidth, fast response times, and a compact, lightweight design. By utilizing silica waveguide technology, complex optical components—such as Y-branch splitters, phase modulators, polarizers, and directional couplers—can be meticulously integrated onto a single substrate, ensuring high reliability and stability compared to bulk optical systems.
Integrated Optic Current Sensors (IOCS) are next-generation optical devices designed for power monitoring and leakage prevention in electrical grid networks. These sensors offer significant advantages over traditional electrical sensors, including EMI-free operation, a linear response over a wide frequency bandwidth, fast response times, and a compact, lightweight design. By utilizing silica waveguide technology, complex optical components—such as Y-branch splitters, phase modulators, polarizers, and directional couplers—can be meticulously integrated onto a single substrate, ensuring high reliability and stability compared to bulk optical systems.
The operation of the IOCS is based on a polarization-rotated reflection interferometry (PRRI) configuration. When an electrical current flows, it generates a magnetic field that causes a phase difference between orthogonal circular polarizations in the sensing fiber due to the Faraday effect. The integrated silica waveguide devices then convert this phase difference into an optical intensity signal. This specific PRRI structure is highly effective at canceling out reciprocal phase fluctuations caused by environmental factors such as temperature changes and mechanical vibrations, allowing for stable and precise current measurement in demanding outdoor conditions.
The operation of the IOCS is based on a polarization-rotated reflection interferometry (PRRI) configuration. When an electrical current flows, it generates a magnetic field that causes a phase difference between orthogonal circular polarizations in the sensing fiber due to the Faraday effect. The integrated silica waveguide devices then convert this phase difference into an optical intensity signal. This specific PRRI structure is highly effective at canceling out reciprocal phase fluctuations caused by environmental factors such as temperature changes and mechanical vibrations, allowing for stable and precise current measurement in demanding outdoor conditions.
Optical Phased Array LiDAR
Optical Phased Array LiDAR
Light detection and ranging (LiDAR) is a fundamental technology for high-precision 3D perception in autonomous mobility and robotics. While conventional mechanical LiDARs face limitations due to their bulk and vibration sensitivity, solid-state optical phased arrays (OPAs) offer a compact and robust alternative compatible with semiconductor manufacturing. Various material systems have been explored for OPA implementation, including silicon for its CMOS compatibility and high thermo-optic (TO) effect, and silicon nitride (SiN) for its low propagation loss and high-power handling. However, silicon suffers from nonlinear absorption at high power, while SiN's weak TO coefficient leads to high driving power requirements.
Light detection and ranging (LiDAR) is a fundamental technology for high-precision 3D perception in autonomous mobility and robotics. While conventional mechanical LiDARs face limitations due to their bulk and vibration sensitivity, solid-state optical phased arrays (OPAs) offer a compact and robust alternative compatible with semiconductor manufacturing. Various material systems have been explored for OPA implementation, including silicon for its CMOS compatibility and high thermo-optic (TO) effect, and silicon nitride (SiN) for its low propagation loss and high-power handling. However, silicon suffers from nonlinear absorption at high power, while SiN's weak TO coefficient leads to high driving power requirements.
To overcome these material-specific drawbacks, researchers have moved toward heterogeneous and monolithic integration strategies. This work specifically utilizes a monolithically integrated polymer-SiN platform to combine the superior TO efficiency of polymers with the low-loss capabilities of SiN. Unlike traditional 2D raster-scanning OPAs that rely on power-intensive wavelength tuning for vertical steering, this system adopts a line-beam scanning architecture. By utilizing an OPA scaled to 128 channels and a custom Geiger-mode avalanche photodiode (Gm-APD) array, the system achieves efficient, high-speed 3D imaging, representing the first complete LiDAR system demonstration on this specific integrated platform
To overcome these material-specific drawbacks, researchers have moved toward heterogeneous and monolithic integration strategies. This work specifically utilizes a monolithically integrated polymer-SiN platform to combine the superior TO efficiency of polymers with the low-loss capabilities of SiN. Unlike traditional 2D raster-scanning OPAs that rely on power-intensive wavelength tuning for vertical steering, this system adopts a line-beam scanning architecture. By utilizing an OPA scaled to 128 channels and a custom Geiger-mode avalanche photodiode (Gm-APD) array, the system achieves efficient, high-speed 3D imaging, representing the first complete LiDAR system demonstration on this specific integrated platform
RF Photonics
RF Photonics
Optical heterodyne-based RF generation is a technique in which two laser beams with slightly different optical frequencies are combined and then detected by a photodetector to produce an electrical signal. The key principle is that the photodetector responds to variations in optical intensity rather than directly measuring the optical field itself. When the two laser beams interfere, they create a time-varying intensity pattern, where the fluctuation rate is determined by the frequency difference between the two lasers. The photodetector converts this intensity variation into an էլectrical signal, resulting in an RF or microwave signal whose frequency corresponds exactly to the difference between the two optical frequencies.
Optical heterodyne-based RF generation is a technique in which two laser beams with slightly different optical frequencies are combined and then detected by a photodetector to produce an electrical signal. The key principle is that the photodetector responds to variations in optical intensity rather than directly measuring the optical field itself. When the two laser beams interfere, they create a time-varying intensity pattern, where the fluctuation rate is determined by the frequency difference between the two lasers. The photodetector converts this intensity variation into an էլectrical signal, resulting in an RF or microwave signal whose frequency corresponds exactly to the difference between the two optical frequencies.
The essence of this approach lies in utilizing the frequency difference between two very high-frequency optical carriers, rather than directly generating RF signals electronically. Because optical frequencies are extremely high, even a small adjustment in the relative frequency of the two lasers can produce RF signals over a very wide range, from gigahertz to terahertz. Moreover, since laser frequencies can be tuned continuously, this method enables fine and seamless frequency control, unlike conventional electronic RF generators that often rely on discrete tuning steps.
The essence of this approach lies in utilizing the frequency difference between two very high-frequency optical carriers, rather than directly generating RF signals electronically. Because optical frequencies are extremely high, even a small adjustment in the relative frequency of the two lasers can produce RF signals over a very wide range, from gigahertz to terahertz. Moreover, since laser frequencies can be tuned continuously, this method enables fine and seamless frequency control, unlike conventional electronic RF generators that often rely on discrete tuning steps.
Polymer Waveguide Devices
Polymer Waveguide Devices
Polymer waveguides have attracted significant attention in integrated photonics due to their strong thermo-optic (TO) effect, which enables efficient refractive index modulation with relatively small temperature changes. This large TO coefficient allows effective phase control in optical devices, making polymer materials particularly suitable for applications such as optical phased arrays and tunable photonic circuits.
Polymer waveguides have attracted significant attention in integrated photonics due to their strong thermo-optic (TO) effect, which enables efficient refractive index modulation with relatively small temperature changes. This large TO coefficient allows effective phase control in optical devices, making polymer materials particularly suitable for applications such as optical phased arrays and tunable photonic circuits.
In addition to their optical properties, polymer waveguides offer high process flexibility and low-cost fabrication. They can be formed using simple techniques such as spin-coating and photolithography, and are compatible with a wide range of substrates and integration schemes. Compared to conventional inorganic materials, polymers enable rapid prototyping and scalable manufacturing, making them an attractive platform for cost-effective photonic integration.
In addition to their optical properties, polymer waveguides offer high process flexibility and low-cost fabrication. They can be formed using simple techniques such as spin-coating and photolithography, and are compatible with a wide range of substrates and integration schemes. Compared to conventional inorganic materials, polymers enable rapid prototyping and scalable manufacturing, making them an attractive platform for cost-effective photonic integration.
Tunable lasers
Tunable lasers
Electro-optic modulators
Electro-optic modulators
Biosensors
Biosensors
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