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Illustration of the optical system parallel to the extended source axis. Not to scale. Light from the laser source (LS) passes through the BK-7 window (W) and is collimated by the first aspheric lens (A). The cylindrical lenses (C) have no optical power along this axis, leaving the beam unchanged. The beam is refocused by the second asphere (A) and passes through a coverslip window (W) before forming the laser image (LI).
