Gou Y.,Chinise Academy of science |
Liu B.,Chinise Academy of science |
Bai Y.,Chinise Academy of science |
Ouyang X.,Chinise Academy of science |
And 3 more authors.
Chinese Journal of Electronics | Year: 2010
A rectangular pulse generator circuit with fast rising and falling edge will be presented in this paper. The generator circuit was designed by controlling the quantity of carriers in the middle layer from regulating forward current of the SRD (Step recovery diode), and then indirectly controlling the pulse width. It is based on the principle that large reverse current will flow through the diode and last for a relatively long time when it is reverse biased. Experimental results have been analyzed in physical level. They are tallied with theoretical results. The circuit can generate rectangular pulses with rise time about 150ps, fall time about 250ps, amplitude about 10V and pulse width adjustable from Ins to 10ns in 50ω load. The trig jitter is less than 5ps and the amplitude jitter is better than 4%.
Chinise Academy Of Science | Date: 2014-07-17
The present invention discloses an optical system for 3D printing and a control method thereof. The system comprises a laser device, a beam expanding system, a beam splitter, a spatial light modulator and a focusing system. The spatial light modulator is connected with a computer and configured to generate a modulation pattern after receiving the target modulation pattern generated by the computer. A light beam emitted by the laser device is expanded into a parallel light beam by the beam expanding system and then irradiates on the beam splitter. A part of the expanded light beam reaches the spatial light modulator for modulation after passing through the beam splitter, then the modulated light beam is reflected to the beam splitter, and a part of the modulated light beam is focused by the focusing system and then irradiates on a target plane for 3D printing.