The proposed IAsLS method is successfully applied to practical Raman spectral baseline correction.

Photoacoustic microscopy (PAM) enables the measurement of properties associated with optical absorption within tissues and complements sophisticated technologies employing optical microscopy. An inadequate frequency response as determined by a piezoelectric ultrasonic transducer results, however, in poor depth resolution and inaccurate measurements of the coefficients of optical absorption. We developed a PAM system configured as an attenuated total reflectance sensor with a ten-layer graphene film sandwiched between a prism and water (the coupling medium) for photoacoustic (PA) wave detection. Transients of the PA pressure cause perturbations in the refractive index of the water thereby changing the polarization-dependent absorption of the graphene film. The signal in PA detection involves recording the difference in the temporal-varying reflectance intensity between the two orthogonally polarized probe beams. The graphene-based sensor has an estimated noise-equivalent-pressure sensitivity of ∼550 Pa over an approximately linear pressure response from 11.0 kPa to 55.0 kPa. Moreover, it enables a much broader PA bandwidth detection of up to ∼150 MHz, primarily dominated by a highly localized evanescent field. From the strong optical absorption of inherent hemoglobin, in vivo label-free PAM imaging provided a three-dimensional viewing of the microvasculature of a mouse ear. These results suggest great potential for graphene-based PAM in biomedical investigations, such as microcirculation studies.

An all-optical modulator with high modulation efficiency based on a graphene-plasmonic slot waveguide structure is proposed. The modulation efficiency is enhanced by the strong interaction between the light and the graphene–plasmonic structure. A modulation efficiency of 0.21 dB μm−1 is obtained with the signal light at a wavelength of 1550 nm. A graphene–plasmonic slot waveguide device of length of 10 μm is fabricated in the experiment. Benefiting from the strong modulation, it is a promising candidate as an on-chip optical modulator with high modulation efficiency and micrometer-scale footprint.

The cooperative perception of the driving environment via the sharing of locally sensed information among automated vehicles plays a fundamental role in ensuring the basic safety of automated driving in complicated public traffic. However, demanding requirements ranging from high data rate and large user density to ultra-high reliability and low latency, are imposed on the 5G network, which is considered the key enabler of cooperative automated driving. In this paper, we propose a novel ultra-dense 5G vehicular network architecture, which features the kinematic information aided user-centric access, to address these requirements. In particular, distributed local access and application centers (LAACs) are designed to perform application implementation and access control collectively, such that the kinematic information of the vehicles extracted at the application layer can be exploited in the dynamic management of network resources to sustain consistently high-performance wireless communications between vehicles and their serving LAACs. Focusing on the uplink transmission of the periodic cooperative sensing messages (CSMs), the possible design of key elements in the kinematic information aided user-centric access, including access point association, radio resource allocation, and mobility support, are discussed. Issues brought about by the practical network deployment and constraints are also considered. In addition, a practical benchmarking access strategy set, which addresses both the reliability and the latency requirements of CSMs, is proposed and evaluated by simulation under the freeway and intersection scenarios. INDEX TERMS Vehicular communications, user-centric access, ultra-reliable and low-latency communications, automated driving, cooperative perception.

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