生物杂化体介导的半人工光合作用:机理、进展及展望

半人工光合系统通过利用人工光合系统与自然光合系统关键功能组分的协同效应以实现太阳能-化学能的转化。生物杂化体介导的半人工光合系统(biohybrid mediated semi-artificial photosynthetic system, BMSAPS)创新性地耦合了光敏剂优异的光捕获特性及生物催化剂高效的催化能力,从而利用太阳能高效驱动特定的化学转化过程。强化光敏剂与生物催化剂微界面间电子的产生、传输及利用是提高BMSAPS性能的关键。本文从BMSAPS的基本原理出发,分析了BMSAPS构建的关键科学问题及研究现状,阐述了该系统光生电子传递的相关机制及研究手段,总结了其在可再生能源转化、二氧化碳减排等方面的研究进展,并就未来的研究方向提出展望。本文有助于加深对BMSAPS的认识,从而为进一步优化其在能源生产和环境修复领域的应用提供理论基础和技术支撑。     

Theoretical analysis of the second-harmonic light power in a biaxial crystal

Theoretical analyses are presented on the critically phase-matched second-harmonic generation （SHG） in a biaxial crystal with the focused fundamental Gaussian beams. The dependence of the second-harmonic light power on the phase matching conditions, focused geometries, walk-off effects, and absorptions are discussed in detail. Expressions are presented for calculating the light power of the types I and II SHGs in the biaxial crystal, applied to optimize the blue light generation with the LiB305 crystal. A maximum conversion efficiency of around 37% is obtained with 798-nm laser power of 500 mW.     

Frequency stabilization of a 399-nm laser by modulation transfer spectroscopy in an ytterbium hollow cathode lamp

The modulation transfer spectroscopy in an ytterbium hollow cathode lamp at 399 nm is measured. The error signal for frequency locking is optimized by measuring the dependences of its slope, linewidth and magnitude on various parameters. Under the optimum condition, the laser frequency at 399 nm can be stabilized. The long-term stability of laser frequency is measured by monitoring the fluorescence signal of the ytterbium atomic beam induced by the locked laser. The laser frequency is shown to be tightly locked, and the stabilized laser is successfully applied to the cooling of ytterbium atoms.