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High-performance 86 μJ, 11.2 fs pulses with a spectrum range of 800–1050 nm are generated based on 1030 nm, 190 fs Yb femtosecond pulses by using multi-plate-based spectral broadening and filtering. Taking advantage of single beam configuration, the obtained pulses have excellent power and spectral stabilities. Since the output spectrum is obtained by spectrally filtering the broadened components, the temporal contrast of the output pulses is enhanced by at least four orders of magnitude. Together with the robust and simple setup, the proposed method is expected to be a competitive option for the generation of seed pulses for 10s–100s petawatt lasers.

Fluorescence microscopy has been widely used in the field of biological imaging, but the disturbance of background noise has always been an unavoidable phenomenon. To obtain a background free image, a virtual HiLo based on edge detection (V-HiLo-ED) method for background removing is proposed, which is different from the existing popular software algorithms that obtain the background-free image by subtracting the estimated background, but the background-free image is directly reconstructed by estimating the foreground. Compared with two other popular software-based methods, the wavelet-based background and noise subtraction algorithm (WBNS) and the rolling ball algorithm (RBA), the V-HiLo-ED owns a better quality on achieving background-free imaging. Compared with hardware-based method such as HiLo method, V-HiLo-ED exhibits almost the same performance but faster speed. In combination with light sheet microscopy, the V-HiLo-ED further improves the signal-to-noise ratio of images with thick light-sheet. These experiment results indicate that the V-HiLo-ED owns the potentiality in many other image applications such as endoscopy.

An improved single-shot fourth-order auto-correlator for temporal contrast measurement is proposed, in which spectral broadening based on self-phase modulation, followed by spectral filtering, is used for sampling pulse generation. When the input pulse energy is 5.5 mJ, the device has a measurement dynamic range of 3 × 10−11, a temporal resolution of approximately 200 fs, and a time window of 68 ps in a single shot. In addition, benefiting from the sCMOS camera data acquisition system, the measurement accuracy is self-verified using simply a tilted glass plate in the optical path of the sampling pulse. Since there is only one input beam without spatiotemporal overlap during sampling pulse generation, the setup is stable and easy to adjust.