Optical read-out of motion is widely used in sensing applications. Recent developments in micro- and nano-optomechanical systems have given rise to on-chip mechanical sensing platforms, potentially ...leading to compact and integrated optical motion sensors. However, these systems typically exploit narrow spectral resonances and therefore require tuneable lasers with narrow linewidth and low spectral noise, which makes the integration of the read-out extremely challenging. Here, we report a step towards the practical application of nanomechanical sensors, by presenting a sensor with ultrawide (∼80 nm) optical bandwidth. It is based on a nanomechanical, three-dimensional directional coupler with integrated dual-channel waveguide photodiodes, and displays small displacement imprecision of only 45 fm/Hz
as well as large dynamic range (>30 nm). The broad optical bandwidth releases the need for a tuneable laser and the on-chip photocurrent read-out replaces the external detector, opening the way to fully-integrated nanomechanical sensors.
Recently, the desired very high throughput of 5G wireless networks drives millimeter-wave (mm-wave) communication into practical applications. A phased array technique is required to increase the ...effective antenna aperture at mm-wave frequency. Integrated solutions of beamforming/beam steering are extremely attractive for practical implementations. After a discussion on the basic principles of radio beam steering, we review and explore the recent advanced integration techniques of silicon-based electronic integrated circuits (EICs), photonic integrated circuits (PICs), and antenna-on-chip (AoC). For EIC, the latest advanced designs of on-chip true time delay (TTD) are explored. Even with such advances, the fundamental loss of a silicon-based EIC still exists, which can be solved by advanced PIC solutions with ultra-broad bandwidth and low loss. Advanced PIC designs for mm-wave beam steering are then reviewed with emphasis on an optical TTD. Different from the mature silicon-based EIC, the photonic integration technology for PIC is still under development. In this paper, we review and explore the potential photonic integration platforms and discuss how a monolithic integration based on photonic membranes fits the photonic mm-wave beam steering application, especially for the ease of EIC and PIC integration on a single chip. To combine EIC, for its accurate and mature fabrication techniques, with PIC, for its ultra-broad bandwidth and low loss, a hierarchical mm-wave beam steering chip with large-array delays realized in PIC and sub-array delays realized in EIC can be a future-proof solution. Moreover, the antenna units can be further integrated on such a chip using AoC techniques. Among the mentioned techniques, the integration trends on device and system levels are discussed extensively.
Indoor optical wireless communication (OWC) using steerable infrared beams is regarded as an important component in future 5G network. Photonic integration technologies can meet the criteria of such ...application, and provide low-cost, high-performance and very compact chips. In this paper, we review the recent development of photonic integration technologies suitable for indoor OWC application, and discuss in detail the current status and future opportunities of several key devices, such as the chip to free space couplers, integrated receivers and transmitters.
The number of photonic components integrated into the same circuit is approaching one million, but so far, this has been without the large-scale integration of active components: lasers, amplifiers, ...and high-speed modulators. Emerging applications in communication, sensing, and computing sectors will benefit from the functionality gained with high-density active–passive integration. Indium phosphide offers the richest possible combinations of active components, but in the past decade, their pace of integration scaling has not kept up with passive components realized in silicon. In this work, we offer a perspective for functional scaling of photonic integrated circuits with actives and passives on InP platforms, in the axes of component miniaturization, areal optimization, and wafer size scaling.
Indium Phosphide Integrated Photonics in Membranes van der Tol, Jos J. G. M.; Yuqing Jiao; Longfei Shen ...
IEEE journal of selected topics in quantum electronics,
2018-Jan.-Feb., 2018-1-00, 20180101, Letnik:
24, Številka:
1
Journal Article
Recenzirano
Integrating electronic and photonic functions has become a major issue in the last decade. This integration requires small photonic circuits that are compatible with CMOS processing. Here an approach ...using an indium phosphide based membrane is reviewed. The high index contrast, leading to micron-sized devices, the full set of photonic functions, including lasers, and the possibility to add these membranes to realized CMOS-circuits, make this an attractive option for hybrid integration. In this paper, the concepts and the required technologies are introduced. A range of realized and proposed membrane devices will be presented, and the prospects of this technique will be discussed.
In this paper, a novel integrated optical wireless receiver/transmitter is presented. The device is realized on an InP membrane platform where active and passive components are integrated ...monolithically. It can be reconfigured to either receiver mode or transmitter mode, by simple control on the operation mode of a photodetector (short SOA). Demonstration of the receiver mode in an indoor optical wireless system has shown 17.4-Gbps OFDM signal transmission, illustrating the potential of this concept.
In this paper, a crosstalk-mitigated transmission scheme in arrayed waveguide grating router (AWGR) based two dimensional infrared beam-steered optical wireless communication (OWC) system is proposed ...for indoor applications. By creating polarization orthogonality between the odd and even AWGR channels, high crosstalk tolerance between spectrally overlapping AWGR channels is realized experimentally. Because two signals with orthogonal polarization states will not beat with each other in a photodiode. The optical crosstalk on the orthogonal polarization state will not generate a beat note upon detection and thus crosstalk in the electrical domain can be largely reduced. Reduced crosstalk leads to a reduction in the required spectral guard band and/or an improved tolerance to spectral overlap, which allows higher spectral efficiency. Moreover, the port number of an AWGR can be increased by simply shortening the spatial gap between adjacent output waveguides on a chip. The higher port number can support the high spatial resolution of the steered OWC system. This technique can also tolerate the wavelength misalignment between AWGRs and lasers, which relaxes the design of low crosstalk AWGRs and high wavelength stable lasers. A 20 Gbit/s data rate, four-level pulse amplitude modulation OWC transmission has been experimentally demonstrated over 1.2-m free-space link. The experimental results show that the proposed scheme can maintain stable, low crosstalk impact with an apparent improvement of the responsivity.
PDF
