The 818-MSCOPE is a Microscope Slide power sensor that measures the optical power at the sample plane in a microscopy setup. The silicon photodiode measures from 350 nm to 1100 nm at optical powers ranging from 3µW to 1W and is designed to be a microscopy power sensor that answers the needs of fluorescence excitation measurements. The sensor has a footprint of 76.0 mm x 25.2 mm matching that of a standard microscope slide. The sensing area is protected and cleanable sealed so that it can measure with in an immersion medium such as water or glycerol as well as in air.

There is a particular challenge with these measurements due to the strongly converging light coming through high N.A. objectives. When attempting to use standard photodiode sensors the measurement will be inaccurate since the responsivities of photodiode sensors have angular dependence and a large percentage of light is incident at high angles. With use of optical epoxy between the diffuser layer and the photodiode, the angular response of 818-MSCOPE is relatively flat, making it insensitive to the high angles of incidence of the incoming light.

818-MSCOPE has a smooth cleanable active area of the sensor. In addition to working in air, it is easy to use water and oil immersion objectives by directly applying the water/oil to the sensor surface.

The 818-MSCOE works the best when focused light from the objective is centered on the active area of the sensor. This can be accomplished by first adjusting the system so that light is centered on the target on the backside of the sensor and then flip the sensor around for the measurement.

Our calibrated photodiode sensors include a full spectral response calibration utilizing NIST-traceable standards calibrated with high-precision equipment maintained in Newport’s optical detector calibration facility. Tight calibration facility and process control allows the tightest calibration uncertainty in industry. Each detector is shipped with the calibration data, which is electronically stored inside the detector's EEPROM. A certificate of calibration as well as the calibration data are shipped with each detector. To maintain accuracy and guarantee performance, Newport recommends annual photodiode detector calibration.