Could You Use Some Feedback?
The ability to control the input quantity of the light “reagent” is a critical factor in obtaining predictable and reproducible outputs from photochemical processes. Controlled light delivery for applications such as quantitative fluorescence microscopy, photodynamic therapy (PDT) photolithography and optogenetics requires intelligent light sources equipped with output monitoring and feedback systems.
At Lumencor, we refer to quantitative light delivery as metered dosage. The necessary monitoring and feedback systems can be optionally installed in all SPECTRA light engine®, SPECTRA X light engine® and AURA light engine® models.
Open loop and closed loop metered dosage systems are available. In both schemes, an onboard photodiode continuously monitors the light output and generates a reference signal. In open loop monitoring, the reference signal is delivered for external display or processing via a BNC connector on the rear panel of the light engine. In the closed loop metered dosage scheme, the reference signal meters the light output and shuts it off when a user-input time-integrated intensity threshold is reached. All closed loop metered dosage functions are controlled from a serially connected computer.
For more information, download our metered dosage data sheet.
- Discrete spectral outputs of 4 solid state light sources are electronically selected and combined according to application requirements.
- The spectral output of each source may be refined by filtering (F).
- Optionally, light engine output may be monitored by a reference photodiode (rPD) to provide feedback control.