Laser techniques and applications in mass spectrometry spectroscopy and photonics

利普森小组将进行质谱、分子光谱和光子学方面的研究。在质谱领域，Lipson和同事们将把短波真空紫外（VUV，波长在100 nm到200 nm之间）激光连接到矩阵辅助激光解吸/电离（MALDI）质谱仪上。MALDI中的中性分子浓度比产生的初级MALDI离子的浓度大得多。因此，用VUV激光对中性离子进行后电离将显著提高MALDI质谱法的灵敏度。Lipson小组还将探索使用可见光吸收激光染料作为MALDI矩阵，具有广泛可调的光学参数振荡器。Lipson小组将利用他们在单光子和多光子激光光谱方面的专业知识来研究小多原子分子（如C2H2Br2）的高能电子态。在这些光谱中分解的精细结构将允许首次建立激发态分子几何形状。Lipson和他的学生们已经开发出了用于制造光子带隙晶体的光学光刻新方法。在这个资助周期中，Lipson小组将探索几个新的方向，包括：能够在可见光到近红外光谱范围内工作的三维晶体的光刻制造；含Si、Ge、Sn基团的高折射率聚合物抗蚀剂的合成与表征，使活性晶体可以一步制得；量子点阵列的制造，结合硼酸钡（BBO）的非线性光子结构的合成和表征，以及生物膜图图化。

The Lipson group will undertake research in mass spectrometry, molecular spectroscopy, and photonics.    In the area of mass spectrometry, Lipson and co-workers will interface a short wavelength vacuum ultraviolet (VUV, wavelengths between 100 nm and 200 nm) laser to a matrix assisted laser desorption/ionization (MALDI) mass spectrometer. The neutral molecule concentration in the MALDI is much larger than that of the primary MALDI ions created. Post-ionization of the neutrals with a VUV laser will therefore significantly enhance the sensitivity of MALDI mass spectrometry by orders of magnitude. The Lipson group will also explore the use of visible light absorbing laser dyes as MALDI matrices with a widely tunable optical parametric oscillator.    The Lipson group will use their expertise in single and multiphoton laser spectroscopy to study the high energy electronic states of small polyatomic molecules such as C2H2Br2.  The fine structure resolved in these spectra will allow excited state molecular geometries to be established for the first time.    Lipson and his students have developed new approaches to optical lithography for the fabrication of photonic band gap crystals. In this funding cycle the Lipson group will explore several new directions including: lithographic fabrication of three-dimensional crystals that are capable of operating in the visible to near infrared spectral range; synthesis and characterization of high index  polymer resists containing Si, Ge and Sn moieties so that active crystals can be made directly in one step; fabrication of quantum dot arrays, synthesis and characterization of nonlinear photonic structures that incorporate beta-barium borate (BBO), and biofilm patterning.