Open-source compact and adaptable fiber-coupled multi-LED platform for biomedical applications.

Multispectral illumination facilitates a broad spectrum of biomedical applications. However, there remains a scarcity of multispectral light sources with a multimode optical fiber output that are spectrally tunable and suitable for small-footprint applications. We present a comprehensive open-source guide for constructing a compact and adaptable fiber-coupled multispectral illumination platform featuring five LEDs in the 455 to 940 nm wavelength range. The key properties of the LED platform, including output power, spectral performance, and stability, are thoroughly characterized. This platform marks the first available multi-LED system, to our knowledge, capable of delivering optical output power in the milliwatt range when coupled to a multimode fiber. Blueprints, assembly instructions, parts lists, source code, and a graphical interface are provided in a Zenodo repository to promote accessibility and expand its use.