相关论文: High sensitivity and large scanning range optical …
We propose a new technique, the use of FBGs (fiber Bragg gratings), for accurate, easy and low cost wavelength calibration of GAIA, RAVE and follow-ups spectra at local Observatories. FBGs mark the spectra with absorption lines, freely…
We propose a scheme to enhance the effective photonic bandwidth exploiting bandgap overlapping of same order or different orders through judiciously chosen aperiodic geometries is spatial dimension. To implement the scheme, we design a…
Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including…
Optical vector analysis (OVA) having the capability to achieve magnitude and phase responses is essential for fabrication and application of emerging optical devices. However, the conventional OVA often have to make compromises among…
This work theoretically investigates wide-spectrum and high-resolution diffraction optical elements (DOE) that are made of stacks of low-resolution binary phase gratings, whereby the two-dimensional grids in different grating layers are…
Continuous aperture arrays (CAPAs) have emerged as a promising physical-layer paradigm for sixth generation (6G) systems, offering spatial degrees of freedom beyond those of conventional discrete antenna arrays. This paper investigates the…
By introducing a columnar null-space region as the reference space, we design a radome that can extend the scanning angle of a phased array antenna (PAA) by a predetermined relationship (e.g. a linear relationship between the incident angle…
Shortwave infrared (SWIR) has various applications, including night vision, remote sensing, and medical imaging. SWIR organic photodetectors (OPDs) offer advantages such as flexibility, cost-effectiveness, and tunable properties, however,…
We propose an efficient method for designing broad beams with spatially flat array factor and efficient power utilization for cell-specific coverage in communication systems equipped with large antenna arrays. To ensure full power…
Millimeter-wave (mmWave) systems use directional beams to support high-rate data communications. Small misalignment between the transmit and receive beams (e.g., due to the mobility) can result in significant drop of the received signal…
Most works evaluating the performance of Multi-User Multiple-Input Multiple-Output (MU-MIMO) systems consider Access Points (APs) with fixed antennas, that is, without any movement capability. Recently, the idea of APs with antenna arrays…
Radio frequency antennas based on Rydberg atom vapor cells can in principle reach sensitivities beyond those of any wire antenna, especially at lower frequencies where long wires are needed to accommodate a growing wavelength. They also…
Myopia is a manifestation of visual impairment caused by an excessively elongated eyeball. Image data is critical material for studying high myopia and pathological myopia. Measurements of spherical equivalent and axial length are the gold…
Two major areas of modern radio astronomy, namely, explosive astrophysical transient phenomena and observations of cosmological structures, are driving the design of aperture arrays towards large numbers of low-cost elements consisting of…
Conventional beamforming with fixed-orientation antenna (FOA) arrays may struggle to effectively enhance signal and/or suppress interference due to significant variations in antenna directive gains over different steering angles. To break…
We present a numerical and experimental study of the impact of phase errors on the performance of large, high-resolution Arrayed Waveguide Gratings (AWG) for applications in astronomy. We use a scalar diffraction model to study the…
Optical phased arrays (OPA) with high integration, fast speed, low power consumption, and high steering resolution are critical components in the emerging photonic integrated circuit (PIC), LiDAR, free space optical communication, 3D…
Collection of weak signals from remote locations is the primary goal and the primary hurdle of optical stand-off detection schemes. Typically, the measured signal is enhanced using large numerical aperture collection optics and high gain…
Metasurface antenna arrays, formed by tiling multiple metasurface subapertures, offer an alternative architecture to electrically large beamsteering arrays often used in radar and communications. The advantages offered by metasurfaces are…
We present a flexible ultra-thin conformal patch antenna array operating in the Industrial, Scientific, and Medical (ISM) band (2.4-2.4835 GHz) for wireless sensor nodes. The antenna was designed on a flexible polyimide film (Kapton HN)…