频域中固体多重光谱烧孔研究

报道固体选通光谱多重光谱烧孔研究的新进展，分析影响多生烧孔形成的一些主要因素，首次报道了在有机材料ＺｎｔｂＰ／ＣＡ／ＰｈＲ的非均匀加宽线内获得一次连续烧出１００多光谱孔的结果，还进一步报道用穿带激光获得更窄线宽的光谱烧孔的情况。     

混合卟啉体系中的光化学烧孔

在有机电子转移型烧孔体系中,混杂两种电子给体-苯并卟啉锌衍生物分子,可增加吸收带的非均匀宽度。本文通过对光谱孔的宽度和烧孔效率的讨论,证明了混杂电子给体的方法对孔宽和烧孔效率无明显影响,可以达到增加此类材料体系的烧孔数目,提高信息存储密度的目的。     

全息光栅光谱烧孔系统和材料特性的研究

建立了全息光栅光谱烧孔技术中，系统的存储密度，读出信噪比和材料特性，读写条件关系的数理模型，计算机模拟定量分析得到了最佳材料特参量空间。研究表明，全息光栅光谱烧孔技术可放宽系统对材料特性的要求，将为烧孔材料研究提供新的理论依据。     

无机材料BaFCl0.5Br0.5：Sm^2＋光子选通光谱烧孔

本文报道了无机材料的BaFCl_(0.5)Br_(0.5):Sm~(2+)的光子选通光谱烧孔.文中叙述了光子选通光谱烧孔的机制.在低温4.2K下进行多孔烧孔和探测.测量了孔的选通性和稳定性.实现了孔的可擦除和重复烧孔.测量结果表明,处于4.2K的BaFCl_(0.5)Br_(0.5):Sm~(2+)样品,在一个非均匀加宽轮廓内可实现1×10~3个以上数目的永久性光谱烧孔.     

M_yM′_(1-y)FCl_xBr_(1-x):Sm~(2+)材料制备光谱性质和光谱烧孔

本文介绍用高温固相扩散方法制备M_yM′_(1-y)FCl_xBr_(1-x):Sm~(2+)(M′=Mg、Ca、Sr、Ba;x,y=1,0.8,…,0),并对这些系列材料发光性质进行了研究.结果表明:非均匀线宽主要受材料中阴离子随机分布影响;材料中x的变化及M,M′的不同或y的变化,对Sm~(2+)的4f~55d能级位置都有影响;对于BaFCl_xBr_(1-x):Sm~(2+)和Sr_yCa_(1-y)FCl_(0.5)Br_(0.5):Sm~(2+)系列材料~5D_0—~7F_0发射峰值与x、y值关系给予了理论解释;选择出较好的光谱烧孔材料Mg_(0.5)Sr_(0.5)FCl_(0.5)Br_(0.5):Sm~(2+),研究了其热猝灭规律,实现了这种材料在77K下的光谱烧孔,对其孔深、孔宽、烧孔能级、存储密度进行了测量计算,为进一步改善材料,研究烧孔机制提供了依据.     

物理学与新型(功能)材料专题系列介绍(Ⅵ) 光谱烧孔──下一代光存储技术

光存储技术由于能实现比其他信息存储技术更高的密度，受到各国重视．然而现行光存储技术的最高存储密度受到激光聚焦光斑最小尺寸限制．各国科学家竞相研究能突破这一限制．实现超高密度的下一代新技术．光子选通光谱烧孔就是其中的佼佼者．中国科学家在提高光子选通光谱烧孔工作温度方面做出了国际同行公认的贡献．光子选通光谱烧孔实际应用还有许多问题有待解决．     

二价钐离子谱线的非均匀加宽、荧光窄化和永久性光谱烧孔

基于光谱烧孔在高密度光存储中的可能应用,研究了谱线非均匀加宽、荧光谱线窄化、高温永久性光谱烧孔、烧孔机理、烧孔动力学过程和光谱孔的热稳定性。在国际上率先设计并研制出二价钐离子掺杂碱土金属氟卤化物混晶高温光谱烧孔体系,实现了室温永久性光谱烧孔,获得了室温寿命300h的光谱孔。利用时间分辨光谱分离出非均匀线形内的各局域组态,比较烧孔前后光谱再分布证实了三价钐离子的电子陷阱作用。利用Block理论分析了烧孔动力学过程。     

依赖于激光线宽的信息写入效率的研究

本工作研究了在聚苯乙烯八乙基卟啉永久性光谱烧孔材料上进行光谱相位编码时域光全息读写中信息写入效率随激光谱带变宽而降低的现象,建立了分子转动引起光谱再分布模型,并计算了不同写入激光线宽下信号衍射效率随曝光量的变化规律,很好地符合了实验结果.     

MyM'1-yFClxBr1-x:Sm2+材料制备光谱性质和光谱烧孔

本文介绍用高温固相扩散方法制备MyM''1-yFClxBr1-x:Sm2+(M''=Mg、Ca、Sr、Ba;x,y=1,0.8,…,0),并对这些系列材料发光性质进行了研究.结果表明:非均匀线宽主要受材料中阴离子随机分布影响;材料中x的变化及M,M''的不同或y的变化,对Sm2+的4f55d能级位置都有影响;对于BaFClxBr1-x:Sm2+和SryCa1-yFCl0.5Br0.5:Sm2+系列材料5D0-7F0发射峰值与x、y值关系给予了理论解释;选择出较好的光谱烧孔材料Mg0.5Sr0.5FCl0.5Br0.5:Sm2+,研究了其热猝灭规律,实现了这种材料在77K下的光谱烧孔,对其孔深、孔宽、烧孔能级、存储密度进行了测量计算,为进一步改善材料,研究烧孔机制提供了依据.     

BaSO4Sm^2＋晶体的光谱及光子选通烧孔效应

首次报道—种新的无机光子造通光谱烧孔材料——BaSO_4:Sm~ (2+)的烧孔效应.并给出了有关光谱性质的实验结果.     

The analysis of factors limiting the maximum output power of broad-area laser diodes

The causes for the saturation of both the continuous-wave and the pulsed output power of broad-area laser diodes driven at very high currents are investigated experimentally and theoretically. The decrease of the gain due to self-heating under continuous-wave operation and spectral holeburning under pulsed operation as well as hetero-barrier carrier leakage and longitudinal spatial holeburning are the dominant mechanisms limiting the maximum achievable output power.     

Investigations of optical coherence properties in an erbium-doped silicate fiber for quantum state storage

We studied optical coherence properties of the 1.53 μm telecommunication transition in an Er³⁺-doped silicate optical fiber through spectral holeburning and photon echoes. We find decoherence times of up to 3.8 μs at a magnetic field of 2.2 T and a temperature of 150 mK. A strong magnetic-field dependent optical dephasing was observed and is believed to arise from an interaction between the electronic Er³⁺ spin and the magnetic moment of tunneling systems in the glass. Furthermore, we observed fine-structure in the Erbium holeburning spectrum originating from superhyperfine interaction with ²⁷Al host nuclei. Our results show that Er³⁺-doped silicate fibers are promising material candidates for quantum state storage.     

用光谱烧孔研究卟啉掺杂的高分子薄膜中电子-声子的相互作用

本文对电子给体、受体双掺杂在高分子薄膜中形成的光谱烧孔体系,做温度循环实验,研究体系中电子-声子的相互作用,得到了表征电子-声子耦合强度的黄昆因子和薄膜中局域振动的声子频率.     

Spectral holeburning and the Stark and Zeeman effects in SrF2:Sm2+

We have observed narrow (40 MHz) persistent spectral holeburning in SrF₂:Sm²⁺ for Sm²⁺ ions in perturbed cubic sites. The transition studied is ⁷F₀?⁵D₀ between the f-electron states. Stark effect measurements show a linear splitting with a coefficient of 0.006 MHz/V cm^-1 and the splitting pattern shows that the site has C_4V symmetry. The C_4V perturbation is very weak and leads to unresolved splittings of cubic T_1g levels of ～2 cm^-1. The nonlinear Zeeman effect was studied using holeburning and the coefficient of 1.04 Hz/G² shows that the predominant magnetic coupling is in the ground state as found recently for CaF₂:Sm²⁺.     

Application of the Raman heterodyne technique for the detection of EPR and ENDOR

Raman heterodyne detection is a coherent optical-RF double resonance technique where the optical and RF fields induce coherence within a three level system and a resultant Raman field is measured using heterodyne detection. This approach has been used previously to detect NMR and more recently EPR. In this paper the parameters that affect the amplitude and signal to noise ratio of the Raman heterodyne signals are considered. The power levels in relation to the oscillator strength and dephasing times, the amplitude and spectrum of the laser frequency jitter in relation to the optical homogeneous linewidths and holeburning rates, and the sample properties such as absorption strength and optical quality, are all factors that affect the Raman signal. The presentation is focused on the Raman heterodyne detected EPR of the nitrogen-vacancy pair centre in diamond making comparisons with Raman heterodyne detected NMR signals obtained for rare earth ion systems. RF-RF double resonance studies, RF holeburning and ENDOR, which give information about the hyperfine levels are also reported for the nitrogen-vacancy centre. The resonance frequencies are in agreement with those predicted from the spin Hamiltonian. The factors affecting the lineshapes and relative intensities of the double resonance signals are discussed.     

Optical holeburning in NaEu(WO4)2

Optical holeburning in the concentrated rare earth compound NaEu(WO₄)₂ is studied. The observation of narrow, 25 MHz, long lived holes and antiholes burned into the ⁷F₀ → ⁵D₀ transition of the Eu³⁺ ion are reported and discussed.     

A new system of photon-gated persistent spectral hole burning material for frequency-domain optical storage

Two-color persistent spectral hole-burning was achieved for the first time for a new system Zn-tetrabenzoporphin-crotonic acid/phenoxy resin at 20 K. The time dependence experiments show that the spectral holes are persistent at the temperature of 20 K. These holes can be erased by laser irradiation and reversible holeburning is performed. The hole width remains almost constant during the erasing process.     

用光谱烧孔研究卟啉掺杂的高分子薄膜中电子－声子的相互作用

本文对电子给体、受体双掺杂在高分子薄膜中形成的光谱烧孔体系，做温度循环实验，研究体系中电子－声子的相互作用，得到了表征电子－声子耦合强度的黄昆因子和薄膜中局域振动的声子频率．     

Stark Hole-Burning Spectroscopy of Cresylviolet Perchlorate in Amorphous Hosts

Stark hole-burning spectroscopy is used to investigate the effective dipole moment change of cresylviolet perchlorate (CVP) in various glass and polymer hosts such as ethanol:methanol (EM), polyvinyl alcohol (PVA), poly (2-hydroxyethyl) methacrylate (PHEMA), polyvinylbutyral (PVB), and formamide. The strong correlation between effective dipole moment change of the guest molecule and the holeburning efficiencies of the host matrices illustrates the sensitivity of the dipole moment change as a direct measure of guest-host interactions. Hole-burning is found to be more efficient as the dipole induced reaction field increases. This relationship is discussed in terms of the unusual hole-burning mechanism suggested for this molecule. The effective dipole moment change of cresylviolet perchlorate ranges from 0.14 to 0.59 Debye.