Spectrum of Light
What is visible light?
The visible spectrum of light runs fromapproximately 380 to 700 nanometers and is
the range detectable by the human eye. This
range features all of the colors of the rainbow
from violet to red.

What about light
we can’t see?
Outside the visible light spectrum arewavelengths that are invisible to the naked eye.
On one end are wavelengths of light which areshorter than violet, including ultraviolet (UV)light, X-rays, and gamma rays. On the other end
with wavelengths longer than red are infrared(IR) light, microwaves, and radio waves.

Light and optical filters
Optical filters for light in the UV, visible
and IR portions of the electromagnetic
spectrum are critical components ina variety of applications from scientificimaging, to telecommunications.

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Chroma’s wholly-owned subsidiary, 89 North,specializes in light solutions for the microscopy
market including their flagship laser diodeilluminator (LDI). Learn more at 89north.com

What is an
optical coating?
Thin film optical coatings use layers of material
with varying refraction indices to alter lightinteraction. By manipulating these layers, we
can adjust the optical filter properties, such astransmission and reflection, for enhancedperformance.
Material one
Material two
Uncoated glass

Learn More: chroma.com

Optical Filters 101
What’s an optical filter?
Optical filters selectively transmit
and/or block light of different
wavelengths passing through them.

Terminology

Astronomy

Machine Vision
Optical filters help
machine vision systems
quickly identify problems,such as bruised produce
by isolating the specificcolors that indicate
quality, ensuring only thebest reaches consumers.

Transmission
The light that is allowed to pass through a filter atspecific wavelengths.

Life Science

When light is caused to bounce off the surface ofa filter rather than passing through. Optical filters
can be designed to reflect specific wavelengths
while transmitting others.

The opposite of transmission. The portion of lightthat is not allowed to pass through the filter. Highblocking eliminates unwanted light. Blocking
happens via either absorption and/or reflection.

Color Matching
Optical filters empowerlife sciences by aiding incellular imaging via
fluorescence microscopy,
chemical analysis
through Raman
spectroscopy, and DNA
analysis in PCR systems.

Reflection

Blocking

Astronomers use opticalfilters to block unwantedlight, isolating specificwavelengths to study
celestial objects'
composition andproperties in detail.

Optical filters are crucial
for color matching,ensuring displays & print
media present colors as
they are meant to beseen.

Shortpass

Longpass

Filters that transmit wavelengths shorter than the
cut-off and block longer wavelengths.

Filters that transmit wavelengths longer than the
cut-on and block shorter wavelengths.

Transmitted Light

Blocked light

Blocked light

Transmitted LightBandpass

Notch

Filters which transmit a specific range (band) ofwavelengths while blocking others.

Filters which block a specific range of wavelengths
from transmitting. The inverse of a bandpass.

Blocked light

TransmittedLight

Blocked light

TransmittedLight

Blocked light

TransmittedLight