干扰过滤器经常用于传播配置中，在该配置中，光线通过过滤器会产生特定的效果（带通路，长通，短通等）。
These filters can also be used in reflective configurations where the filter reflects wanted light and rejects or absorbs the transmitted light.
光通常不会吸收interference filters;所有光都反映或传输（如图1所示）。
Some exceptions are known, especially in IR and UV, where the inherent features of the materials cause specific wavelengths to be absorbed. Scatter can also be observed at a small amount in most thin films.
申请such as fluorescence and beam combining take advantage of this ability to reflect particular wavelengths while transmitting others.
Laser beams of different wavelengths are focused onto a single optical axis in beam combining. Dichroic mirrors are utilized in fluorescence to reflect excitation wavelengths and transmit fluorescence signals.
当没有吸收时，反射和发射光的总和为100％。
Figure 1.%T and %R of a filter at a 45° angle of incidence. These add up to 100% for most interference filters in the visible wavelength regime.
挡板过滤器 -A reflective filter assembly is referred to as a ‘baffle filter’ by Omega. This is where multiple reflecting filters are positioned to produce the desired effect. Various configurations can be devised to focus the beam in a particular direction or to stabilize the optical axis (outlined in Figure 2).
Alternatively, the separate filters can be used as steering or folding mirrors in the customer’s optical system design.
要考虑的一个因素是，该滤波器将在准直的光束中以单个入射角（AOI）的形式更成功（最陡峭的边缘和最高的传输或反射）。
S和P极化的分裂通常发生在较高的AOIS处，但是在设计过滤器时可以控制其中一些。
Figure 2.一些挡板滤波器在45°和22.5°AOI上设计。这些设计概念几乎可以纳入任何光学系统。
应用和性能
UV band-pass filters with visible light blocking -Most materials used for thin-film coating begin through the absorption of light in the UV (lower than approximately 350 nm).
吸收使得很难以高透射率产生紫外线过滤器，同时同时阻止整个可见光谱。
Induced transparency in metals (MDM design) is the traditional method used to achieve a particular level of transmission in the UV and strong visible blocking (shown in Figure 3). This filter category usually has a high blocking level, but a low transmission rate (less than 50%).
纯粹的介电堆栈（图3）可以实现较高的传输和较陡的边缘，这些材料与紫外线兼容的材料的材料可以实现。亚博网站下载除非使用非常大的堆栈，否则阻塞范围是有限的。
用22.5°AOI切换到反射（挡板盒）配置band-pass并成功地阻断了通过在组件中使用吸收环氧树脂引起的。
Figure 3.使用2弹跳反射滤波器比较MDM和透射紫外线过滤器。顶部: linear scale,Bottom: log scale to emphasize blocking. The reflective filter maintains narrow bandwidth, high throughput, and blocking over a wide wavelength range.
狭窄的缺口拒绝过滤器 -Due to the nature of thin-film interference filters, transmission notch filter designs are highly challenging, specifically when a high OD is required over a very limited wavelength.
欧米茄擅长生产非常高的传输狭窄带通滤波器。它们可以在反射时创建狭窄的凹口。
图4。顶部：标准的透射凹口设计，具有2个AOIS设计的2弹性反射凹口。Bottom：日志量表中显示的相同数据以显示阻塞（红色和蓝色曲线中的OD 6）。
Utilizing this design technique, the width of the notch at 50% T can be reduced from approximately 16.5 nm (in the average transmission filter) to 6.2 nm wide at 45° and 4.3 wide at 22.5° AOI.
由于两个极化状态（S和P）的分裂，通过增加AOI来扩大凹口。在图4的底部可以看到这种现象是黑色痕迹中的双浸。
Omega helps its customers in ‘thinking inside the box’ with their continuing optical design projects.
This information has been sourced, reviewed and adapted from materials provided by Omega Optical, Inc.
有关此消息来源的更多信息，请访问Omega Optical，Inc。