Single-frequency 45-mJ pulses from a MOPA system using an Er,Yb:glass planar waveguide amplifier and a large mode area Er-doped fiber amplifier.

We demonstrate a master oscillator power amplifier (MOPA) system that emits single-frequency high-energy optical pulses at 1540 nm using an Er,Yb:glass planar waveguide amplifier and a large mode area Er-doped fiber amplifier. A double under-cladding and a 50-µm-thick core structure are employed for the planar waveguide amplifier to increase the output energy without degrading the beam quality. A pulse energy of 45.

Demonstration of the 1.53-µm coherent DIAL for simultaneous profiling of water vapor density and wind speed.

The 1.53-µm coherent differential absorption lidar (DIAL) is demonstrated for the simultaneous profiling of water vapor (HO) density and wind speed. The optical setup is fiber-based.

Wavelength selection and measurement error theoretical analysis on ground-based coherent differential absorption lidar using 1.53 µm wavelength for simultaneous vertical profiling of water vapor density and wind speed: publisher's note.

This publisher's note amends the title in Appl. Opt.59, 2238 (2020).

Wavelength selection and measurement error theoretical analysis on ground-based coherent differential absorption lidar using 1.53 µm wavelength for simultaneous vertical profiling of water vapor density and wind speed.

A feasibility study of coherent differential absorption lidar is conducted using a 1.53-µm wavelength for simultaneously retrieving the water vapor density and wind speed profiles. We selected the ON and OFF wavelengths to be 1531.

1.55-μm high-peak, high-average-power laser amplifier using an Er,Yb:glass planar waveguide for wind sensing coherent Doppler lidar.

We have developed a high-gain, high-peak-power laser amplifier at an eye-safe 1.55 μm wavelength using an Er,Yb:glass planar waveguide for wind sensing coherent Doppler lidars (CDLs). Our planar waveguide is free from stimulated Brillouin scattering and realizes high gain thanks to its multi-bounce optical-path configuration.

[Operator Dose Measurements and Image Quality Assessment in Computed Tomography Fluoroscopy Using Bismuth Sheet].

Objective: The purpose of this study was to assess the dose reduction and the image quality using bismuth sheets during the computed tomography fluoroscopy (CTF).

Materials And Methods: The bismuth sheets of 1-mm thick were put on the upper mylar ring to reduce the frontal X-ray. The dose rates of an operator were measured using a torso phantom in the patient position during the CTF.

Sequentially timed all-optical mapping photography (STAMP) utilizing spectral filtering.

We propose and experimentally demonstrate a new method called SF-STAMP for sequentially timed all-optical mapping photography (STAMP) that utilizes spectral filtering. SF-STAMP is composed of a diffractive optical element (DOE), a band-pass filter, and two Fourier transform lenses. Using a linearly frequency-chirped pulse and converting the wavelength to the time axis, we realize single-shot ultrafast burst imaging.

Saturation of 640-nm absorption in Cr⁴⁺:YAG for an InGaN laser diode pumped passively Q-switched Pr³⁺:YLF laser.

We measure the absorption recovery time, the ground- and excited-state absorption cross sections of a Cr4+:YAG crystal at 640 nm for the first time. A pump-probe measurement reveals the existence of two recovery times of 26 ns and 5.6 μs.

Generation of photon-number squeezed states with a fiber-optic symmetric interferometer.

We numerically and experimentally demonstrate photon-number squeezed state generation with a symmetric fiber interferometer in an 800-nm wavelength and compared with an asymmetric fiber interferometer, although photon-number squeezed pulses have been generated only with asymmetric interferometers. Even though we obtain -1.0dB squeezing with an asymmetric fiber interferometer, since perfect spectral phase and intensity matching between displacement and signal pulses are achieved with a symmetric fiber interferometer, we obtain better squeezing of -3.

Two-dimensional spatiotemporal focusing of femtosecond pulses and its applications in microscopy.

We demonstrate and theoretically analyze the two-dimensional spatiotemporal focusing of femtosecond pulses by utilizing a two-dimensional spectral disperser. Compared with spatiotemporal focusing with a diffraction grating, it can achieve widefield illumination with better sectioning ability for a multiphoton excitation process. By utilizing paraxial approximation, our analytical method improves the axial confinement ability and identifies that the free spectra range (FSR) of the two-dimensional spectral disperser affects the out-of-focus multiphoton excitation intensity due to the temporal self-imaging effect.

In-phased second harmonic wave array generation with intra-Talbot-cavity frequency-doubling.

The Talbot cavity is one promising method to synchronize the phase of a laser array. However, it does not achieve the lowest array mode with the same phase but the highest array mode with the anti-phase between every two adjacent lasers, which is called out-phase locking. Consequently, their far-field images exhibit 2-peak profiles.

Spatiotemporal control of femtosecond plasmon using plasmon response functions measured by near-field scanning optical microscopy (NSOM).

Spectral interferometry combined with near-field scanning optical microscopy is applied in the spatiotemporal characterization of femtosecond plasmon localized at gold nanostructures and surface plasmon polariton in an air-gap waveguide. Based on the plasmon response function in both the amplitude and the phase obtained from the measurements, we deterministically tailored the femtosecond plasmon pulse by shaping the femtosecond excitation laser pulses.

Photon-number squeezing with a noisy femtosecond fiber laser amplifier source using a collinear balanced detection technique.

We experimentally demonstrate photon-number squeezing at 1.55 μm using a noisy erbium-doped fiber amplifier (EDFA). We employ a collinear balanced detection (CBD) technique, where the intensity noise at a specific radio frequency is canceled between two pulse trains.

Phase locking in a Nd:YVO₄ waveguide laser array using Talbot cavity.

We demonstrated phase-locking in a laser-diode-array-pumped Nd:YVO₄ laser array (15 emitters) using a Talbot cavity. The Nd:YVO₄ slab crystal was coated by dielectric material for claddings and formed a planar waveguide for the vertical mode. To stabilize the horizontal array mode, periodical thermal lenses were generated by controlling the heat flow.

Factors affecting the yield of endoscopic transpapillary bile duct biopsy for the diagnosis of pancreatic head cancer.

Background: Transpapillary biliary biopsy (TBB) is a simple endoscopic technique that can be performed during an initial biliary drainage session. This procedure has the potential to reduce the load of another tissue sampling in cases of pancreatic head cancer (PHC) with biliary stricture. The aim of this study is to identify factors associated with a positive outcome using TBB for PHC.

Photon number squeezing of ultrabroadband laser pulses generated by microstructure fibers.

To the best of our knowledge, we demonstrate for the first time the generation of photon number squeezing by spectral filtering for ultrabroadband light generated by microstructure fibers at 800 nm. A maximum squeezing of 4.6 dB is observed, corresponding to 10.