Chinese Academy of Sciences

Pei Huang

Min Wu

Kun Zhao

Yong Huang

Shigenori Kuga

Shaobo Fang

Zhiyi Wei

Yitan Gao

Methods and devices are described for performing an all-phase measurement of an ultra-fast laser pulse having a spectral range of greater than one octave. The ultra-fast laser pulse may be split into a first beam comprising a fundamental light with a wavelength &#x3bb;and a second beam comprising a light with a wavelength 2&#x3bb;. The light with the wavelength 2&#x3bb;may be frequency doubled to a light with a wavelength &#x3bb;to generate an interference with the fundamental light. Fourier transform may be performed on an interference spectrum of the interference, and a relative envelope delay (RED) between the fundamental light and the frequency doubled light and a carrier envelope phase (CEP) may be acquired based on a result of the Fourier transform.

Methods and apparatus for measuring and locking ultra-fast laser pulses

A method for preparing stably dispersed cellulose nanofibers comprises the following steps: 1) mixing cellulose and an organic solvent, the percentage of the cellulose being 1% to 15% in weight; 2) adding an esterification agent into the resultant mixture of step 1), the molar ratio of the esterification agent to the cellulose being from 1:0.1 to 4; and 3) physically breaking the resultant mixture of step 2) until a suspension liquid with stably dispersed cellulose nanofibers of 2-1000 nm in diameter and 10-100 &#x3bc;m in length is obtained, an esterification reaction of hydroxyl group(s) on the surface of cellulose fibers occurring at the time of the breaking. Also disclosed are dispersed cellulose nanofibers with improved compatibility to the matrix than the untreated cellulose and an improved strength of the composite materials.

Method for preparing cellulose nanofiber capable of being stably dispersed

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Beijing, China

Pei Huang