Abstract: An optical detector comprises a plurality of pixels, each pixel comprising a photodiode operable to detect light incident on that pixel and to generate a signal indicative of an intensity of that light. The plurality of pixels comprises a plurality of pixel pairs, and for each pixel pair, in a configuration mode, the detector is arranged to compare the signal generated by a first pixel of the pair with the signal generated by a second pixel of the pair. A method of optical detection is also described, as is a system incorporating the described optical detector.

Abstract: An optical detector comprises a plurality of pixels, each pixel comprising a photodiode operable to detect light incident on that pixel and to generate a signal indicative of an intensity of that light. The plurality of pixels comprises a plurality of pixel pairs, and for each pixel pair, in a configuration mode, the detector is arranged to compare the signal generated by a first pixel of the pair with the signal generated by a second pixel of the pair. A method of optical detection is also described, as is a system incorporating the described optical detector.

Abstract: A sample 10 is measured by generating ultrasound at 12, for example by using a laser 22 and spatial light modulator 26. The ultrasound is detected at 16, for example by optical beam deflection techniques. A characteristic of the generation at 12 is swept across a range of values to vary the efficiency of generation of ultrasound. The value of the characteristic, which corresponds with the peak amplitude detected at 16, is identified to provide a measure of the acoustic velocity at the region 12. The method is executed at a plurality of sites 12, 20 to provide a set of spatially resolved measurements of the sample 10. This allows an image of the sample to be created.

Abstract: A sample 10 is measured by generating ultrasound at 12, for example by using a laser 22 and spatial light modulator 26. The ultrasound is detected at 16, for example by optical beam deflection techniques. A characteristic of the generation at 12 is swept across a range of values to vary the efficiency of generation of ultrasound. The value of the characteristic, which corresponds with the peak amplitude detected at 16, is identified to provide a measure of the acoustic velocity at the region 12. The method is executed at a plurality of sites 12, 20 to provide a set of spatially resolved measurements of the sample 10. This allows an image of the sample to be created.