The invention provides a confocal microscope or endoscope, having a source of coherent light for illuminating a sample, and an imaging optical fibre bundle ( 82 ) for receiving return light, whereby the fibre bundle ( 82 ) provides a return channel for fluorescent return light ( 78 ). The optical fibre bundle ( 82 ) preferably preserves, between entry and exit ends of the bundle, the relative spatial coordinates of the cores of individual fibres constituting the bundle.
