McLeod Robert R, Honda Tokuyuki
Department of Electrical and Computer Engineering, University of Colorado, Campus Box 425, Boulder, Colorado 80309, USA.
Opt Lett. 2005 Oct 1;30(19):2647-9. doi: 10.1364/ol.30.002647.
Compact spectrometers fabricated by placing a wedged etalon or a linear variable filter in front of a linear photodiode array typically do not exhibit the spectral resolution of a parallel filter of the same finesse. A theoretical analysis of the beam emerging from a wedged etalon is shown to predict a comalike aberration, explaining the loss in resolution. This analysis also predicts a focused beam waist whose axial position depends on the incidence angle, indicating that resolution can be improved by placing this waist on the detector. These results are experimentally confirmed in a multicavity linear variable filter to achieve 0.09 nm spectral resolution at 1550 nm.
通过将楔形标准具或线性可变滤光片放置在线性光电二极管阵列前面制造的紧凑型光谱仪，通常无法展现出具有相同精细度的平行滤光片的光谱分辨率。对从楔形标准具出射的光束进行的理论分析表明，会预测到一种类彗形像差，这解释了分辨率的损失。该分析还预测到一个聚焦光束腰斑，其轴向位置取决于入射角，这表明通过将此腰斑放置在探测器上可以提高分辨率。这些结果在多腔线性可变滤光片中得到了实验证实，在1550 nm处实现了0.09 nm的光谱分辨率。
