(A) Overall layout of the confocal system, showing microscope and scan system mounted on an optical bench, rackmount cabinet containing electronic drive circuits, and computers for image acquisition and processing.

(B) Optical schematic of the real-time confocal scanner. The components forming the scan system are mounted on an optical table, and are interfaced through the video port (VP) of an Olympus IX50 inverted microscope. A separate UV flash photolysis system is used for photolysis of caged compounds, and is mounted on the epifluorescence port (EP) of the microscope. S1, S2 = shutters; M1–M4 = fullyreflecting, broadband coated mirrors; DM = dichroic mirror, l= 500 nm; YG = y-scan off-axis scan mirror; RS = resonant scanning mirror; L1 = plano-concave lens, f = –50 cm; SL = scan lens, 10x Olympus eyepiece lens; KB = adjustable knife blade aperture; BF = barrier filter, 510 nm long pass; ID = iris diaphragm; PMT photomultiplier tube (Hamamatsu R-928).

(C) Rendering of the scan head assembly.

(A) Electronic drive circuitry and interface to video acquisition card.

(B) Waveforms of x- and y-scan signals, and corresponding sync pulses. Note that the timing of pixel clock pulses is indicated only diagrammatically. All sync pulses are TTL levels.