Supplementary document for Extended angular-spectrum modeling (EASM) of light energy transport in scattering media - 6146928.pdf

detailed description of EASM, detailed data in figure

Supplementary document for Extended angular-spectrum modeling (EASM) of light energy transport in scattering media - 6139066.pdf

This document provides supplementary information to “Extended angular-spectrum modeling (EASM) of light energy transport in scattering media”. It includes the detailed description of EASM, detailed data in figures and experimental setup

Watt-level, kHz pulsed ASE source with pulse-width close to round-trip time based on Nd:GdVO4 bounce geometry

We demonstrate a watt-level, kHz nanosecond-pulse ASE source with its pulse-width being close to its round-trip time. The ASE uses a Nd:GdVO4 high gain bounce geometry structure without an output coupler. Using an EOQ (electro-optics Q-switch) device with high extinction-ratio, the pulse-width reaches 2.28, 1.73 and 1.17 ns under three effective cavity lengths, respectively. All these pulse-widths are close to the round-trip time of the corresponding effective cavity lengths. With the pulse-width being 1.17 ns, maximum output energy of 120 {\mu}J and peak power of 100 kW are achieved. This study offers a convenient method to obtain high-peak-power short pulses, comparing with cavity-dumping method

Truncated triangular diffraction lattices and orbital-angular-momentum detection of vortex SU(2) geometric modes

We for the first time report the truncated diffraction with a triangular aperture of the SU(2) geometric modes and propose a method to detect the complicated orbital angular momentum (OAM) of an SU(2) wave-packet, to the best of our knowledge. As a special vortex beam, a nonplanar SU(2) mode carrying special intensity and OAM distributions brings exotic patterns in truncated diffraction lattice. A meshy structure is unveiled therein by adjusting the illuminated aperture in vicinity of the partial OAM regions, which can be elaborately used to evaluate the partial topological charge and OAM of an SU(2) wave-packet by counting the dark holes in the mesh. Moreover, through controlling the size and position of the aperture at the center region, the truncated triangular lattice can be close to the classical spot-array lattice for measuring the center OAM. These effects being fully validated by theoretical simulations greatly extend the versatility of topological structures detection of special beams

Acoustic-optic Q-switched cavityless weak-feedback laser based on Nd:GdVO4 bounce geometry

An AOQ (acoustic-optic Q-switched) laser with cavityless weak-feedback configuration is demonstrated based on a Nd:GdVO4 bounce geometry. The laser can operate at a repetition up to 500 kHz with the output power above 4W. The pulse-width at 100 kHz reaches 5.2 ns, which is 4.3 times the round-trip time. A theory of Q-switched cavityless weak-feedback laser is proposed for the first time, to our best knowledge. This theory is very suitable for analyzing short pulses comparable to round-trip time. By utilizing the theory, simulation is implemented for our experimental conditions. The consistence between the simulation and the experimental results proves the validity of our theory

Visualization 3.mp4

The quadrant-separable singularity manipulation along the radial directio

Visualization 4.mp4

The quadrant-separable singularity manipulation along the angular directio

Dual-wavelength vortex beam with high stability in diode-pumped Yb:CaGdAlO4 Laser

We present a stable dual-wavelength vortex beam carrying orbital angular momentum (OAM) with two spectral peaks separated by a few terahertz in diode-pumped Yb:CaGdAlO4 (CALGO) laser. The dual-wavelength spectrum is controlled by the pump power and off-axis loss in laser resonator, arising from the broad emission bandwidth of Yb:CALGO. The OAM beam is obtained by a pair of cylindrical lens that serves as an {\pi}/2 convertor for the high-order Hermite-Gaussian modes. The stability is verifed that the 1 h OAM beam with two spectral peaks at 1046.1 nm and 1057.2 nm (3.01 THz interval) can steadily operate for more than three hours. It has great potential for scaling the application for OAM beams in Terahertz spectroscopy, high-resolution interferometry, and so on

Visualization 5.mp4

Singularities evolution with different initial phase differenc

Short pulse close to round-trip time generated by cavityless high gain Nd:GdVO4 bounce geometry

In this paper, laser pulses with pulse-widths approach to the round-trip time are generated by utilizing a cavityless high gain Nd:GdVO4 bounce geometry. By adopting an EOQ (electro-optics Q-switch), pulse-widths of 1.36 ns, 1.82 ns, and 2.39 ns are achieved at three effective cavity lengths respectively. All these pulse-widths are close to the round-trip time of corresponding effective cavity lengths. Moreover, the output power reaches watt-level and the repetition rate is kHz-level, meanwhile the M2 factor is less than 1.3. Spectrally, the laser has a continuous spectrum with 10 dB linewidth of 0.2 nm