This CoriantTypesYesNo switch (default no) enables Automatic Laser Shutdown (ALS) at the near end of an STM-64 (10 Gb/s SDH) client port, a laser-safety feature that turns the transmit laser off when the receive path detects a loss of signal. An administrator enables this on facilities where personnel might handle disconnected fibers, so a broken or unplugged fiber does not leave a live laser exposed. For example, turning on near-end ALS on STM-64 means that if the receive fiber is unplugged, this port's own transmit laser automatically shuts down rather than continuing to emit into an open connector.