Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Polgenix Inc., 11000 Cedar Ave, Cleveland, Ohio 44106, USA;
Published: July 2016
AI Article Synopsis
Article Abstract
Two-photon fluorescence microscopy (TPM) is now being used routinely to image live cells for extended periods deep within tissues, including the retina and other structures within the eye . However, very low laser power is a requirement to obtain TPM images of the retina safely. Unfortunately, a reduction in laser power also reduces the signal-to-noise ratio of collected images, making it difficult to visualize structural details. Here, image registration and averaging methods applied to TPM images of the eye in living animals (without the need for auxiliary hardware) demonstrate the structural information obtained with laser power down to 1 mW. Image registration provided between 1.4% and 13.0% improvement in image quality compared to averaging images without registrations when using a high-fluorescence template, and between 0.2% and 12.0% when employing the average of collected images as the template. Also, a diminishing return on image quality when more images were used to obtain the averaged image is shown. This work provides a foundation for obtaining informative TPM images with laser powers of 1 mW, compared to previous levels for imaging mice ranging between 6.3 mW [Palczewska G., Nat Med.20, 785 (2014) Sharma R., Biomed. Opt. Express4, 1285 (2013)].
Purpose: To compare the refractive prediction accuracy of the Optiwave Refractive Analysis (ORA) SYSTEM with the Barrett True-K (BTK) formula in calculating intraocular lens (IOL) power in eyes that underwent cataract surgery after previous myopic photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK).
Methods: This retrospective study evaluated patients aged ≥22 years with prior myopic PRK or LASIK who underwent unilateral or bilateral cataract removal and monofocal IOL implantation using the ORA SYSTEM at 177 sites in the United States. Two datasets were analyzed: All Eyes (ie, all eligible eyes) and First Surgery Eyes (ie, each patient's first implanted eye).
Cascaded Raman fiber lasers (CRFLs) with wavelength-independent feedback can provide power at any wavelength in near-IR regions. However, broad feedback leads to a broad output spectrum, decreasing spectral power density at a desired wavelength. The output characteristics of CRFLs can be controlled by controlling the feedback.
We experimentally demonstrate a cost-effective dual-polarization quadrature phase shift keying (DP-QPSK) coherent passive optical network (PON) system that operates at 100 Gbits/s/λ. This system utilizes distributed feedback lasers (DFBs) and a carrier recovery algorithm facilitated by a bifunctional frequency-domain pilot tone (FPT). To reduce costs in coherent PON implementations, low-cost DFBs are employed as the sole light sources, replacing the more expensive external cavity lasers (ECLs) at both the optical line terminal (OLT) and the optical network units (ONUs).
We report on continuous high-harmonic generation (HHG) at 1 kHz repetition rate from a liquid-sheet plasma mirror driven by relativistic-intensity near-single-cycle light transients. Through precise control of both the surface plasma density gradient and the driving light waveform, we can produce highly stable and reproducible extreme ultraviolet spectral quasi-continua, expected to correspond to the generation of stable kHz-trains of isolated attosecond pulses in the time domain. This confirms the exciting potential of liquid-sheet targets as one of the building blocks of future high-power attosecond lasers.
We demonstrate a hybrid integrated optical frequency comb amplifier composed of a silicon carbide microcomb and a lithium niobate waveguide amplifier, which generates a 10-dB on-chip gain for the C+L band microcombs under 1480-nm laser pumping and an 8-dB gain under 980-nm laser pumping. It will solve the problem of low output power of microcombs and can be applied in various scenarios such as optical communication, lidar, optical computing, astronomical detection, atomic clocks, and more.
