Chiral Propagation of Plasmon Polaritons due to Competing Anisotropies in a Twisted Photonic Heterostructure.

We theoretically demonstrate chiral propagation of plasmon polaritons and show that it is more efficient and easier to control than the recently observed chiral shear phonon polaritons. We consider plasmon polaritons created in an anisotropic two-dimensional (2D) material twisted with respect to an anisotropic substrate to best exploit the competition between anisotropic electron-electron interactions and the anisotropic electronic structure of the host material. Gate voltage and twist angle are then used for precise control of the chiral plasmon polaritons, overcoming the existing restrictions with chiral phonon polaritons.

Intra-Zero-Energy Landau Level Crossings in Bilayer Graphene at High Electric Fields.

The highly tunable band structure of the zero-energy Landau level (zLL) of bilayer graphene makes it an ideal platform for engineering novel quantum states. However, the zero-energy Landau level at high electric fields has remained largely unexplored. Here we present magnetotransport measurements of bilayer graphene in high transverse electric fields.

Flattening conduction and valence bands for interlayer excitons in a moiré MoS/WSe heterobilayer.

We explore the flatness of conduction and valence bands of interlayer excitons in MoS/WSe van der Waals heterobilayers, tuned by interlayer twist angle, pressure, and external electric field. We employ an efficient continuum model where the moiré pattern from lattice mismatch and/or twisting is represented by an equivalent mesoscopic periodic potential. We demonstrate that the mismatch moiré potential is too weak to produce significant flattening.

Chester Supersolid of Spatially Indirect Excitons in Double-Layer Semiconductor Heterostructures.

A supersolid, a counterintuitive quantum state in which a rigid lattice of particles flows without resistance, has to date not been unambiguously realized. Here we reveal a supersolid ground state of excitons in a double-layer semiconductor heterostructure over a wide range of layer separations outside the focus of recent experiments. This supersolid conforms to the original Chester supersolid with one exciton per supersolid site, as distinct from the alternative version reported in cold-atom systems of a periodic density modulation or clustering of the superfluid.

Low-voltage surface-normal electroabsorption modulators.

Surface-normal electroabsorption modulators (SNEAMs) are appealing for short-reach communication systems because of their outstanding properties, such as ultrawide bandwidth and polarization-insensitive response; however, due to their small active volumes, large voltage swings are typically required to obtain the best performance. Here we propose and demonstrate a novel, to the best of our knowledge, design that dramatically reduces the voltage needed by SNEAMs and significantly increases their extinction ratio. By shrinking the multiple quantum well stack of SNEAMs to the minimum and by optimizing their reflectivity with dielectric coatings of suitable refractive index and thickness, we obtain modulators that require drive voltages of only 1-2.

Peta-bit-per-second optical communications system using a standard cladding diameter 15-mode fiber.

Data rates in optical fiber networks have increased exponentially over the past decades and core-networks are expected to operate in the peta-bit-per-second regime by 2030. As current single-mode fiber-based transmission systems are reaching their capacity limits, space-division multiplexing has been investigated as a means to increase the per-fiber capacity. Of all space-division multiplexing fibers proposed to date, multi-mode fibers have the highest spatial channel density, as signals traveling in orthogonal fiber modes share the same fiber-core.

Time reversed optical waves by arbitrary vector spatiotemporal field generation.

Lossless linear wave propagation is symmetric in time, a principle which can be used to create time reversed waves. Such waves are special "pre-scattered" spatiotemporal fields, which propagate through a complex medium as if observing a scattering process in reverse, entering the medium as a complicated spatiotemporal field and arriving after propagation as a desired target field, such as a spatiotemporal focus. Time reversed waves have previously been demonstrated for relatively low frequency phenomena such as acoustics, water waves and microwaves.

Multiport swept-wavelength interferometer with laser phase noise mitigation employing a broadband ultra-weak FBG array.

Optical vector network analyzers (OVNAs) based on swept-wavelength interferometry are applied widely in optical metrology and sensing to measure the complex transfer functions of optical components, devices, and fibers. Phase noise from laser sweep nonlinearities degrades the measurement quality as the distance increases and limits the usage of the OVNA in characterizing systems with long impulse responses as required in space-division multiplexing links with a high mode count or in the presence of large modal differential group delay (DGD). In this Letter, we use a densely distributed broadband ultra-weak fiber Bragg grating array to directly measure the distortion due to phase noise at a 5-m increment up to 400 m and use this measured data to directly eliminate the distortion.

PAM-4 transmission up to 160 Gb/s with surface-normal electro-absorption modulators.

We report multi-level modulation in polarization-independent surface-normal electro-absorption modulators (SNEAMs). Four-level pulse amplitude modulation (PAM-4) at a line rate of 44 Gb/s is demonstrated on a fully packaged SNEAM with a 30 µm active area diameter and a 14 GHz electro-optic bandwidth. High-capacity PAM-4 transmission at 112 and 160 Gb/s is demonstrated on an unpackaged SNEAM chip, with a 15 µm active area diameter and ultrawide electro-optic bandwidth (≫65).

Power insensitive surface-normal electroabsorption modulators.

Surface-normal electroabsorption modulators (SNEAMs) have unique electro-optic modulation properties; however, their behavior and performance at high light intensity is affected by thermal nonlinearities that take place in the modulator active volume. Here we show a novel, to the best of our knowledge, approach to make SNEAMs insensitive to optical power without the use of power-hungry heaters or feedback control systems. By passively compensating for the thermo-optic dependence of the SNEAM resonant cavity, we obtain an eight-fold reduction in the wavelength shift of the SNEAM response at 4 dBm of input power.

Laguerre-Gaussian mode sorter.

Exploiting a particular wave property for a particular application necessitates components capable of discriminating in the basis of that property. While spectral or polarisation decomposition can be straightforward, spatial decomposition is inherently more difficult and few options exist regardless of wave type. Fourier decomposition by a lens is a rare simple example of a spatial decomposition of great practical importance and practical simplicity; a two-dimensional decomposition of a beam into its linear momentum components.

Fiber-optic transmission and networking: the previous 20 and the next 20 years [Invited].

Celebrating the 20 anniversary of Optics Express, this paper reviews the evolution of optical fiber communication systems, and through a look at the previous 20 years attempts to extrapolate fiber-optic technology needs and potential solution paths over the coming 20 years. Well aware that 20-year extrapolations are inherently associated with great uncertainties, we still hope that taking a significantly longer-term view than most texts in this field will provide the reader with a broader perspective and will encourage the much needed out-of-the-box thinking to solve the very significant technology scaling problems ahead of us. Focusing on the optical transport and switching layer, we cover aspects of large-scale spatial multiplexing, massive opto-electronic arrays and holistic optics-electronics-DSP integration, as well as optical node architectures for switching and multiplexing of spatial and spectral superchannels.

Anaesthetic management and complications during hypophysectomy in 37 cats with acromegaly.

Objectives: The aim of this study was to describe the anaesthetic management and perianaesthetic complications encountered during hypophysectomy surgery in acromegalic cats. We explored relationships between animal demographic data, the anaesthetic protocol used and presence of perioperative complications.

Methods: Cats having undergone hypophysectomy surgery for the treatment of feline acromegaly at a single veterinary referral hospital were identified from hospital records.

Evidence from Quantum Monte Carlo Simulations of Large-Gap Superfluidity and BCS-BEC Crossover in Double Electron-Hole Layers.

We report quantum Monte Carlo evidence of the existence of large gap superfluidity in electron-hole double layers over wide density ranges. The superfluid parameters evolve from normal state to BEC with decreasing density, with the BCS state restricted to a tiny range of densities due to the strong screening of Coulomb interactions, which causes the gap to rapidly become large near the onset of superfluidity. The superfluid properties exhibit similarities to ultracold fermions and iron-based superconductors, suggesting an underlying universal behavior of BCS-BEC crossovers in pairing systems.

Rapid postoperative recurrence of a cranial multilobular tumor of bone in a young dog.

Although resection of multilobular tumors of bone can be associated with a good prognosis and long disease-free intervals in dogs, osteosarcomatous transformation should be considered a cause for rapid recurrence of clinical signs.

Mutational Analysis of Gene Fusions Predicts Novel MHC Class I-Restricted T-Cell Epitopes and Immune Signatures in a Subset of Prostate Cancer.

Gene fusions are frequently found in prostate cancer and may result in the formation of unique chimeric amino acid sequences (CASQ) that span the breakpoint of two fused gene products. This study evaluated the potential for fusion-derived CASQs to be a source of tumor neoepitopes, and determined their relationship to patterns of immune signatures in prostate cancer patients. A computational strategy was used to identify CASQs and their corresponding predicted MHC class I epitopes using RNA-Seq data from The Cancer Genome Atlas of prostate tumors.

Dynamic Lumbosacral Magnetic Resonance Imaging in a Dog with Tethered Cord Syndrome with a Tight Filum Terminale.

A 1-year and 11-month- old English Cocker Spaniel was evaluated for clinical signs of progressive right pelvic limb lameness and urinary incontinence. Neurological examination was suggestive of a lesion localized to the L4-S3 spinal cord segments. No abnormalities were seen on magnetic resonance imaging (MRI) performed in the dog in dorsal recumbency and the hips in a neutral position and the conus medullaris ended halfway the vertebral body of L7.

COMPARISON OF ISOFLURANE AND SEVOFLURANE FOR SHORT-TERM ANESTHESIA IN MEERKATS (SURICATA SURICATTA)-ARE THERE BENEFITS THAT OUTWEIGH COSTS?

Meerkats ( Suricata suricatta ) are routinely anesthetized with isoflurane in zoo and field settings. Twenty healthy adult meerkats of mixed age and sex held in the Zoological Society of London's collection were anesthetized with 4% isoflurane by face mask for routine health examinations. The procedure was repeated 5 mo later in the same group of animals utilizing sevoflurane at 5% for induction, and again 3 mo later with sevoflurane at 6.

Immune Modulation by Androgen Deprivation and Radiation Therapy: Implications for Prostate Cancer Immunotherapy.

Prostate cancer patients often receive androgen deprivation therapy (ADT) in combination with radiation therapy (RT). Recent evidence suggests that both ADT and RT have immune modulatory properties. First, ADT can cause infiltration of lymphocytes into the prostate, although it remains unclear whether the influx of lymphocytes is beneficial, particularly with the advent of new classes of androgen blockers.

Ultrasound-guided subcostal oblique transversus abdominis plane block in canine cadavers.

Objectives: To describe the ultrasound-guided transversus abdominis plane (TAP) block using a subcostal oblique approach in dog cadavers and to evaluate the spread of a methylene blue solution using a multiple-injection technique.

Study Design: Prospective, descriptive, experimental anatomic study.

Animals: Nine adult Beagle cadavers weighing a mean ± standard deviation of 13 ± 2 kg.

A description of a technique for ultrasound-guided lumbar plexus catheter in dogs: cadaveric study.

Objective: To describe an ultrasound-guided approach for lumbar plexus catheter placement in dogs.

Study Design: Prospective experimental cadaveric study.

Animals: Eleven thawed canine cadavers (13 ± 2 kg).

Tumor vascularity in ovarian cancer: T cells need breathing room.

Tumor-infiltrating lymphocytes (TILs) are crucial for effective antitumor responses. However, hypoxia can skew T-cell differentiation and function, thereby perturbing TILs. We have demonstrated that TILs and their immune function are associated with tumor vascularization.