Designing a custom spectrometer

We will delve in more detail here on the types of questions we ask our customers when starting a spectrometer design program and the various stages of development.

Some recent spectrophotometer development tasks included:

• Miniaturize a current lab prototype

• Automate an existing instrument

• Improve or redesign an existing spectrophotometer

• Increase the range of samples tested

• Add image capturing to an existing setup

• Provide electronics and software design

These programs may include design optimization, improvement of a proven concept prototype, or development of a completely new concept.  We work then to design and manufacture the optical and electronic parts, develop the firmware and software for data processing, manufacture optical and mechanical custom components, and assemble the desired number of working prototypes.

Zemax model of a spectrophotometer Illumination system using cylindrical lenses

Zemax model of illumination system with a lenticular lens arrays for uniform slit illumination

Depending on the stages of development, certain components may have been previously determined or may require development

Common Spectrophotometer Components

• Illumination system type

• Light acquisition system type

• Fiber collimator

• Cylindrical lens

• Diffraction grating

• Aspherical mirror

• Image sensor/ Camera

• Display screen

• Secondary optical channel with lens and detector

A Czerny-Turner scheme layout of a monochromator, a critical spectrophotometer component that separates a band of light based on refraction with a prism or diffraction (grating)

Given the defined components, we review with our client the key performance and system construction details.

Key Parameters

• Size of system

• Size of area analyzed

• Working distance

• Minimum and maximum exposure time

• Point of incident light

• Incident and excident light axis polar and altitude angle

• Beam shaping and positioning

• Operating wavelength range

• FOV

• Magnification

• Focus range

• Shutter speed

• Resolution

• Signal to noise ratio

• Transmission considerations

• Polarization considerations

• Scattering considerations

• Distortion considerations

• Electronic board power supply range

Requirements about sensitivity, working wavelengths, and environmental conditions for the spectrophotometer can be defined during a feasibility study if unknown at the start.

Some customers may have additional requirements to meet aesthetics and ergonomic concerns.  This typically happens once proof of concept is established and the project moves to the next phase of development. In the second stage, we:

• Address any thermal, environmental constraints

• Optimize the optical system for production volume

• Update the optical elements and their placement

• Prepare technical documentation and testing criteria

 

Need assistance designing a custom spectrometer? Learn more about our design services here.