Abstract
An optical delay line is used to form a 45‐m‐long CO2 laser cavity. Continuous locking of the longitudinal cavity modes has been observed with SF6 or BCl3 in the cavity. The laser output is a continuous train of uniform amplitude pulses occurring at 300‐nsec intervals. The observed pulse widths of 60–70 nsec correspond to locking five or six modes in a 13‐ to 18‐MHz bandwidth.