Multi-Wavelength Laser Arrays for Spectroscopy

Butterfly packaged multi-wavelength source showing bonded lasers, waveguide array and combined coupled optical output

Packaged Multi-Wavelength Laser Array with multiple lasers coupled into a single fiber.

Optical spectrum of the MWS, showing each laser channel's optical characteristics.

Spectrum of each fiber-coupled laser.

Multi-wavelength source showing one of the lower-wavelength channels illuminating the access waveguide and fiber output.

A single channel illuminating the access waveguide and output fiber.

Near Infrared Spectroscopy has traditionally been accomplished using filtered white light sources and rotating gratings or detector arrays. This approach suffers from limited signal to noise ratio, high power consumption, and optical complexity.

Praevium, under funding from the US department of Agriculture and the National Cancer Institute, has developed miniaturized multi-wavelength laser arrays that offer essentially tunable radiation covering critical portions of the vis/NIR range (650-1700nm), at the output of a multi-mode optical fiber.

Such sources have increased signal to noise ratio relative to filtered white light, particularly in applications where high spatial resolution is required. Additionally, lasers can be high-speed modulated to obtain frequency domain as well as steady state measurements. Laser wavelengths can be customized to target a wide variety of specific applications, such as breast cancer detection, assessment of body hydration status, or quantification of agricultural constituents.

The multi-wavelength laser is not currently a commercial product. However, if you are interested in a funded development effort to customize these devices for a specific application, please contact us at

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