Related papers: Metal-Mesh Linear Variable Filter for Far-Infrared…
The far-infrared (IR) region is rich with information needed to characterize interstellar dust and to investigate the cold outer planets of the solar system and their icy moons. The proposed sub-orbital observatory the Balloon Experiment…
Since the start of full science operations from 2004, the Submillimeter Array has been implementing plans to expand IF bandwidths and upgrade receivers and cryostats. Metal mesh low-pass filters were designed to block infrared (IR)…
We present high-performance terahertz (THz) metal-mesh bandpass filters developed to mitigate direct detection effects in sensitive THz receivers based on superconducting hot-electron bolometer (HEB) mixers. These metal-mesh filters are…
Abstract: An induced-transmission filter (ITF) uses an ultrathin layer of metal positioned at an electric-field node within a dielectric thin-film bandpass filter to select one transmission band while suppressing other transmission bands…
A new class of wideband bandpass filters based on using thick metallic bars as microwave resonators, instead of common microstrip lines, is presented. These bars provide a series of advantages over fully planar printed technologies,…
Long-wave infrared (LWIR, 8-12 $\mu m$ wavelengths) is a spectral band of vital importance to thermal imaging. Conventional LWIR optics made from single-crystalline Ge and chalcogenide glasses are bulky and fragile. The challenge is…
Mid-infrared (MIR) spectroscopy is a powerful technique employed for a variety of applications, including gas sensing, industrial inspection, astronomy, surveillance, and imaging. Thin-film narrowband interference filters, targeted to…
We report on the development of transmission-line reflectionless filters operating with passbands at 100 GHz and 230 GHz, and stopband absorption up to 500 GHz, the highest operating frequencies yet recorded for such filters. The designs…
We developed a wideband quasi-optical band-pass filter covering 170-520 GHz by exploiting the recent advancements in commercially available flexible printed circuit (FPC) fabrication technologies. We designed and fabricated a three-layered…
The frequency dependent beampatterns of an active sonar projector filters the acoustic signal that is transmitted into the medium, also known as the transmit waveform. This filtering encodes information about the target's bearing relative…
Many signal processing applications require digital filters with variable frequency characteristics, especially the filters with variable bandwidth. Due to their linear phase and inherent stability, variable bandwidth finite impulse…
We report on the design of an all-mirror wavefront-division interferometer capable of spectroscopic studies across multiple spectral ranges$\unicode{x2013}$from the plasma frequencies of metals to terahertz wavelengths and beyond. The…
Laser-Induced Fluorescence (LIF) spectroscopy is an essential tool for probing ion and atom velocity distribution functions (VDFs) in complex plasmas. VDFs carry information about kinetic properties of the species critical for plasma…
Narrow-band filters are often used to constrain the chemical composition of astronomical objects through photometry. A challenge to derive accurate photometry is that narrow-band filters are based on interference of multiple reflections and…
Moving the detection wavelength in vibrational sum-frequency generation (VSFG) spectroscopy to the near-infrared (> 700 nm) can potentially enable the study of molecular interfaces absorbing in the visible and give access to buried…
We propose a high thermal conductivity infrared (IR) filter using alumina for use in millimeter wave detection systems. We constructed a prototype two-layer anti-reflection (AR) coated alumina filter with a diameter of 100mm and a thickness…
The desire for higher sensitivity has driven ground-based cosmic microwave background (CMB) experiments to employ ever larger focal planes, which in turn require larger reimaging optics. Practical limits to the maximum size of these optics…
Broadband refractive optics realized from high index materials provide compelling design solutions for the next generation of observatories for the Cosmic Microwave Background (CMB), and for sub-millimeter astronomy. In this paper, work is…
We demonstrate numerically the diffraction-free propagation of sub-wavelength sized optical beams through simple elements built of metal-dielectric multilayers. The proposed metamaterial consists of silver and a high refractive index…
Nonlinear interferometers allow for mid-infrared spectroscopy with near-infrared detection using correlated photons. Previous implementations have demonstrated a spectral resolution limited by spectrally selective detection. In our work, we…