Resource Library

With a virtually unlimited lifetime and superior performance, Semrock optical filters help ensure the best possible images. They may be the easiest and least expensive way to improve the performance of your microscope when compared to the cost of upgrading cameras and objectives. Learn More

Optical filters are generally comprised of multi-layered thin-film coatings on plane, parallel glass substrates. All Semrock filters use a single substrate with coatings on one or both sides to maximize transmission and reliability. The glass substrate is not always perfectly flat before coating and the intrinsic stress of hard coatings can cause slight bending of the substrate. Fortunately, this bending has no noticeable effect on light transmitted through an optical filter at or near normal incidence. For light incident at high angles of incidence, like for a 45° dichroic beamsplitter, the bent substrate creates a slight divergence of the transmitted beam axis similar to the effect of a small wedge in the substrate. Unless the radius of curvature is very small (much less than one meter) the quality of the transmitted beam remains largely unaffected. Learn More

Transition width and edge steepness are two terms often used to describe the spectral properties of edge filters and it is important to know that these two terms are related, but not interchangeable. Transition Width is the maximum distance between the laser line (where OD > 6) and the 50% transmission point. Edge Steepness is the actual steepness measured from the OD 6 point to the 50% transmission point. Learn More

All Semrock filters are hard coated with sophisticated Ion Beam Sputtering (IBS) technology, resulting in patented state-of-the-art filters with extremely durable hard glass coatings on a single hard glass substrate. No absorbing glass and no lamination is necessary. The result is exceptionally durable "no burn out" fluorescence filters of the highest performance. Learn More

All Semrock filters are inspected in accordance with industry standards established for optical components. Learn how our team inspects each filter. Learn More

The "color" of light is generally identified by the distribution of power or intensity as a function of wavelength λ. Visible light has a wavelength that ranges from about 400 nm to just over 700 nm. Sometimes it is convenient to describe light in terms of units called "wavenumbers," where the wavenumber w is typically measured in units of cm-1 ("inverse centimeters") and is simply equal to the inverse of the wavelength, and is therefore proportional to frequency. Learn More

In many high-performance Raman systems with microscopic imaging capabilities or highly sensitive remote probes it is desirable for the excitation laser beam and the Raman-shifted signal light to share a common light path. Illustrations in this tech note describe the two layouts and the ideal filters for each system. Learn More

Semrock uses individual PET-G packaging for standard-size catalog filters. This packaging allows Semrock to keep the parts cleaner, reduce potential defects caused by shipping & handling, and utilizes 100% recyclable PET materials. Learn More

The RazorEdge edge filters and the StopLine notch filter are both available with OD>6 blocking of the laser line. Should you use an edge filter or a notch filter to block the laser line in your Raman system? Learn more. Learn More

High-performance optical mirrors are a key component to most system designs. From bench-top setups to high-end lab instrumentation, mirrors can enable a reduced system footprint, combine multiple sources, help to form images, or other purposes. This article provides a high-level, basic overview of some of the key specification parameters to consider when selecting the appropriate mirror for your optical system. Learn More