An eight-frame gated microchannel plate (MCP) camera and a gating electrical pulse are described in this article. The gating electrical pulse is obtained by first generating a high voltage fast step pulse using avalanche transistors in Marx bank configuration, and then shaping it using avalanche diodes. The high voltage fast step pulse is about 200ps in fall time and 4kV in amplitude. The gating pulse wave form with width of 160ps and amplitude of 2.5kV is achieved. Each frame photocathode coated with gold on the MCP is part of a 12Ω transmission line with open circuit end driven by the gating electrical pulse. The camera is tested by illuminating its photocathode with ultraviolet laser pulses, 266nm in wavelength, which shows exposure time as short as 120ps.

An x-ray framing camera based on pulse-dilation technology is reported. This camera first dilates the electron signal generated from a pulsed photo-cathode (PC), and then detects the dilated electron pulse by using a gated microchannel plate (MCP). While the PC is only applied with a direct current (DC) voltage, the camera’s temporal resolution without pulse-dilation is about 81 ps. It is the gated MCP’s temporal resolution. While an excitation pulse is applied on the PC, the electron pulse’s temporal width is dilated, and the resolution is improved to 14 ps. Furthermore, the camera’s temporal resolution uniformity is measured and simulated. The results show a 3.5 × drop in temporal resolution along the pulse propagation direction, due to the 5 × decrease of the PC excitation pulse gradient.

We report a deep penetration microscopic imaging method with a non-diffracting Airy beam. The direct mapping of volume imaging in free space shows that the axial imaging range of the Airy beam is approximately 4 times that of the traditional Gaussian beam along the axial direction while maintaining a narrow lateral width. Benefiting from its non-diffracting property, the microscopic imaging with Airy beam illumination can acquire image structures through turbid medium and capture a volumetric image in a single frame. We demonstrate the penetration ability of the Airy microscopic imaging through a strongly scattering environment with 633 nm and 780 nm lasers. The performances of the volumetric imaging method were evaluated using HeLa cells and isolated mouse kidney tissue. The thick sample was scanned layer by layer in the Gaussian mode, however, in the Airy mode, the three-dimensional (3D) structure information was projected onto a two-dimensional (2D) image, which vastly increased the volume imaging speed. To show the characteristics of the Airy microscope, we performed dynamic volumetric imaging on the isolated mouse kidney tissue with two-photon.

An x-ray detector using a pulse-dilation technology to achieve high temporal resolution is reported. The electron pulse generated from the photo-cathode (PC) is first dilated by a pulse-dilation device and then imaged onto the microchannel plate (MCP) by a magnetic lens imaging system. Finally, the dilated electron pulse is detected by a gated MCP. A resolution of 14 ps is achieved. In addition, the synchronous gating is studied in the dilation x-ray detector without a 1:1 image ratio. The results show that while the time of flight (TOF) of the electrons is identical, the MCP gating pulse can be timed relative to the PC excitation pulse to gate the dilated electron signal in a single area, and they are unsynchronized in the other area. To avoid the single area synchronization effect, the magnetic lens imaging system used in the detector should allow photoelectrons with a large energy spread to be imaged onto the MCP. This effect can also be reduced by using an MCP gating pulse with a width larger than 500 ps. Moreover, a 1:1 image ratio can avoid this effect. Furthermore, a decreasing electron TOF can eliminate the single area synchronization effect.