热辐射体的光谱"蓝移"浅谈

看了《红外物理中热辐射的光谱“蓝移”及与之有关的问题》和《热辐射光谱“蓝移”问题的商榷》两文 ,本文对其测试条件提出质疑 ,并着重阐述了光谱发生“蓝移”是“过程中”的现象 ,并不违反热力学三定律。     

热辐射光谱“蓝移”问题的商榷

对《红外物理中热辐射体的光谱“蓝移”及与之有关的问题》一文从实验及物理两方面     

对<热辐射光谱"蓝移"问题的商榷>一文的答复

<红外技术>第21卷第5期(1999年9月)发表了赵举廉同志的文章<热辐射光谱"蓝移"问题的商榷>[1]"(以下简称<商榷>),对我们发表在<红外技术>的论文<红外物理中热辐射体的光谱"蓝移"及与之有关的问题>[2](以下简称<蓝移>)提出质疑.<商榷>一文确有值得我们吸取的观点,但同时对我们的论文也有较多误解,一些概念和提法是我们不能同意的.特别是<商榷)一文的评论,仅只针对<蓝移>作为"问题的提出"的很小的一个部分,而对我们提出的许多论据和有关的物理、数学的分析却完全绕开了,从而也就将"实际的热辐射体的辐射光谱分布,相对于黑体的光谱分布,到底是否有蓝移存在"这样一个主题绕开了.     

红外物理中热辐射体的光谱“蓝移”及与之有关的问题（下）

对红外物理,红外技术中传统的“灰体”概念提出新的看法,发现全发射率εｈ〈１的实际发热体的热辐射,其光谱分布相对于绝对黑体,必宁要向短波方向移动,亦即有“蓝移”的出现,对所提出的论断,已从多种途径作了物理和数学上的论证。最后,还对红外技术中与此有关的一些问题,提出建议与评述。     

多孔硅室温光致发光研究

采用电化学和化学溶蚀法在体单晶硅上制备了高孔度多孔硅;室温下测量了蓝光激发的光致可见光谱,发现样品在大气环境中保存时光致发光谱随时间有显著“蓝移”,并渐趋稳定,谱峰位置“蓝移”约40nm;文中给出了发光膜的平面透射电镜形貌和电子衍射照片。“蓝移”和电镜照片的结果能用量子尺寸效应说明。文中还给出了喇曼谱仪上测得的光致发光谱和多孔硅的喇曼位移峰。     

色散介质中超短脉冲厄米-高斯光束在相位奇点附近的光谱异常特性

基于索末菲(Sommerfeld)衍射积分公式,对色散介质中超短脉冲厄米-高斯光束在相位奇点附近的光谱异常行为进行了研究,并与真空中的光谱异常行为进行了比较.结果表明,超短脉冲厄米-高斯光束的轴上光谱蓝移,蓝移大小与群速度及脉冲宽度有关,而与群速度色散无关.色散介质中的相对光谱移动略小于真空中的相对光谱移动,脉冲宽度越大,相对光谱移动越小.光谱开关的位置与横向距离、传输介质和厄米函数阶数m,n有关,而与脉冲宽度无关.光谱开关的横向距离小于真空中的相应阶的光谱开关的横向距离,并且随光谱开关的阶数增加,真空和色散介质的相对光谱移动均缓慢减小.     

多孔硅的光致发光谱

本文介绍了用电化学腐蚀的阳极氧化工艺，在硅衬底上制备多孔硅（ＰＳ）薄膜，实验测定了多孔硅薄膜的光致发光谱（ＰＬ），发现光致发光谱峰值波长随阳极氧化时间、ＨＦ浸泡时间或置于空气中自然氧化时间增加而向短方向移动（“蓝移”）．文章用量子限制效应（ＱＣＥ）理论解释了上述实验结果，并提出了在多孔硅发光机制中还存在表面态及实物质在发光中的作用。     

纳米晶体颗粒的声子布里渊光谱研究

以声子格林函数理论为基础,推导了简立方纳米晶体颗粒的声子布里渊光谱的线形公式,并给出了数值计算的结果。计算结果表明,在纳米晶体颗粒中,声子能带分裂为一系列能级,由于平移对称性被破坏,准动量不再守恒,除了长波长声子外,短波长声子也参与了布里渊散射,致使布里渊光谱发生了分裂和蓝移,分裂间隙和蓝移随纳米晶体颗粒尺寸的减小而增加,该项研究成果可应用于纳米晶体颗粒尺寸的测量。     

部分相干光经色差透镜聚焦后的光谱开关现象

实验研究了宽带部分相干光被会聚透镜聚焦，着重研究了聚焦透镜的色差效应对在透镜几何成像面的聚焦光场光谱的影响。结果表明，与入射光的光谱相比，在几何成像面的某些点部分相干光的归一化光谱呈现蓝移，而另一些点则呈现了红移；特别是某些点处光归一化光谱分裂为2个波峰，在临界点处光谱位移发生突变，即出现了光谱开关现象；归一化光谱的2个波峰在一些点处还可以继续分裂，且在临界点处的归一化光谱短波长区域再次出现光谱开关现象。这一结果对光谱的高精度测量以及新型的光谱开关的研究具有较重要的意义。     

退火对BST薄膜光学特性影响的研究

利用射频磁控溅射在硅和石英基片上制备了Ba0.6Sr0.4TiO3(BST)薄膜。并用气氛炉和快速晶化炉对其进行退火,比较了退火前后的XRD谱和光致发光光谱,结果表明,退火后,氧缺位减少,发光光谱在紫外区的峰位发生红移,在可见光区的峰位却发生蓝移,荧光峰半高宽变窄。同时,透射光谱表明,薄膜的禁带宽度变窄。     

再论热辐射体光谱"蓝移"及"红移"

大多数的热辐射体都是选择性辐射体.现在却被当灰体处理,其光谱分布较灰体必然有"蓝移"和"红移"的现象.给出了金属钨作为选择性辐射体及灰体的辐射公式,并进行了比较.     

基于电弧等离子体的光纤光栅快速退火的研究

为了实现光纤布喇格光栅的快速退火,采用高温电弧等离子体热处理光纤光栅的方法,设计了相关实验进行验证。由实验可知,透射谱深度23dB、中心波长1552.09nm、3dB带宽0.2784nm的光纤光栅,经电弧等离子体放电扫描后,光纤光栅的透射谱深度减小,3dB带宽变窄,中心波长蓝移;随着重复扫描次数的增加,各参量变化趋势减缓,最终透射谱深度减小13dB、中心波长蓝移0.84nm、3dB带宽变窄0.1013nm;将电弧等离子体处理后的光纤光栅放入高温炉24h退火后,透射谱深度、中心波长、3dB带宽均不再发生变化。结果表明,将电弧等离子体用于光纤布喇格光栅的退火处理是可行的,并且具有周期短、涂覆层无损伤的优点。     

Abnormal blue shift of InGaN micro-size light emitting diodes

Blue InGaN micro-size light emitting diodes (LEDs) with diameters from 3 to 70 μm have been fabricated. An ion implantation technique and a 12 μm electro-ridge were used to simplify the fabrication processes. The 3–70 μm LEDs exhibiting a large emission of photon blue shift (40–240 meV) were observed in electro-luminescence (EL) spectra. The dependence of the blue shift on size is studied. The characteristics of the micro-size LEDs are also investigated numerically with the use of an advanced physical model of semiconductor devices (APSYS). The experimental measurements and simulation results are in close agreement for maximum blue shift. Base on the simulation, the difference between blue shift caused by band filling effect and red shift caused by lateral carrier confinement are approximately the same. Hence, the maximum blue shift increases when the size of micro-size LED increases because of decreased red shift resulted from thermal effect.     

用光谱法研究光敏剂血卟啉单甲醚对肿瘤细胞光动力作用的分子机制

测定了光敏剂血卟啉单甲醚对人宫颈癌细胞HeLa光敏作用后的傅里叶红外光谱。结果显示:光敏作用后,HeLa细胞磷酸二酯基团的对称伸缩振动峰1085cm^-1和不对称伸缩振动峰1246cm^-1蓝移,强度下降:蛋白质酰胺Ⅰ带1656cm^-1发生蓝移,酰胺Ⅱ带1546cm^-1出现红移;CH₂对称伸缩振动峰2858cm^-1,峰位蓝移2cm^-1,峰值明显减弱:细胞的蛋白质和核酸谱峰面积比值D1085/D1546降低。提示细胞中的DNA、蛋白质和磷脂结构受到损伤。结果表明:DNA、蛋白质和磷脂是血卟啉单甲醚光敏作用的主要靶分子。     

Thermal frequency drift suppression in tunable DFB lasers by plasmainduced frequency shift enhancement

The authors propose enhanced-plasma-effect (EPE) lasers for coherent optical frequency division multiplexed networks. In the EPE lasers, the blue frequency shift due to the plasma effect is enhanced by incorporating a very thick p-side optical guide layer as a carrier reservoir for multiple quantum-well distributed feedback laser and it surpasses the red frequency shift due to the thermal effect. The results of demonstrating a frequency step response maintained in the blue shift region and an enhanced blue shift frequency modulation response over the whole modulation frequency range from DC are presented for the first time     

Asymmetric quantum wells with enhanced QCSE: modulation behaviour and application for integrated laser/modulator

We have optimized asymmetric InGaAsP QWs with respect to the quantum confined Stark effect (QCSE). We have found structures with a red shift of 40 meV at a field of 70 kV/cm. Moreover, it was our aim to find structures with a strong blue shift. A new principle for the integration of a laser and a modulator is presented, which is based on the application of blue shift asymmetric QW's in the active layer for laser and modulator simultaneously. A calculation of the laser and modulation properties for a QW-structure with 27 meV blue shift at a field variation of 70 kV/cm is presented.     

Si3N4无杂质空位诱导InGaAs/InP 量子阱结构带隙的蓝移

用光荧光谱和二次离子质谱的方法,研究了由Si3N4电介质薄膜引起的无杂质空位诱导InGaAs/InP多量子阱结构的带隙蓝移。实验中选用Si3N4作为电介质层,用以产生空位,并经快速热退火处理。实验结果表明,带隙蓝移同退火时间和退火温度有关,合理选用退火条件可以控制带隙的蓝移量。二次离子质谱分析表明,电介质盖层Si3N4和快速热退火导致量子阱中阱和垒之间互扩,这种互扩是导致带隙蓝移的主要原因。     

Carrier-induced energy shift in GaAs/AlGaAs multiple quantum welllaser diodes

Emission energy shift due to high carrier density at threshold in multiple quantum well (MQW) laser diodes is investigated theoretically. This energy shift is evaluated through the Schrodinger and the Poisson equations self-consistently as well as the calculation of the gain spectra with carrier-dependent lifetime broadening. The band filling and the gain broadening effects show a blue shift on the emission energy. Larger number of wells, lower barrier height, or wider well thickness, reduces the blue shift dependence on the carrier density. At high injections, this blue shift is offset by the bandgap shrinkage effect, which displays smaller influence on MQW's. While the carrier density is further increased, the transition due to the second quantized state is found in single quantum wells, however it is difficult to be observed in MQW's     

GaN基白光LED温度特性实验研究

实验研究了恒流驱动条件下,GaN基白光LED的正向电压、发光光谱和发光效率随环境温度的变化情况.结果表明,在输入电流恒定的情况下,随着温度的升高,结电压和发光强度与温度具有良好的线性关系,并且GaN基白光LED的发光颜色总是向蓝光漂移,而小电流驱动时比大电流驱动时蓝光漂移更明显.根据实验结果,分析了器件的最佳额定工作电流.

Abstract：

Under a constant driving current, the changes of the forward voltage, emission spectrum and luminous efficiency of GaN-based White LEDs with the ambient temperature are studied experimentally. It is found that the forward voltage and the luminous intensity depend on the temperature linearly with constant injection current, and luminous colors of GaN-based White LEDs always shift towards blue. And the blue shift with low driving current is more obvious than that with high driving current. According to the results, the best rated operating current of GaN-based white LEDs is discussed.