Box 1. Light sources for laboratory light delivery.

There are several options for expanding in-house access to light sources at a wide variety of wavelengths. The most readily available are listed below with their wavelength ranges.

Mercury Arc lamps	250–600 nm	Broad-spectra mercury-arc lamps are available from several suppliers (e.g., Excelitas) whose output can be refined to desired wavelengths with bandpass filters (typically to capture major outputs at 254, 365, 405, 436, 546, and/or 579 nm). These light sources are comparatively inexpensive and high powered.
LEDs	250–700 nm	A wide variety of wavelengths and intensities are available from several manufacturers. ThorLabs offers multiwavelength arrays of LEDs for use in microscopy that can be easily adapted for light delivery on the benchtop. One can also purchase individual LEDs from companies (e.g., LED Engin) for user control over wavelength and power. While LEDs offer changeable intensity, their emission can be broad, with the full-width half maximum (FWHM) value extending ±10–20 nm beyond the reported wavelength.
Lasers	250–900 nm	Laser pointers may be repurposed for laboratory research, and are often desirable for their highly focused beam and narrow bandwidth; lasers are often centered within ±1 nm of the reported wavelength. Zbolt offers a selection of high powered, constant-on laser pointers that are useful for benchtop experiments and the irradiation of a small area. Though highly focused, laser pointers cannot change intensity, so experiments testing variable light intensities are impossible.