概要（Overview）

ELS‐4000 is designed and engineered to perform at 400 Hz and 4 W with a narrower spectral bandwidth (2 pm) and a wavelength stability of better than ±0.25 pm. In addition, the pulse‐to‐pulse stability has been improved in stepper‐mode operation. The ELS‐4000 also employs a new microprocessor controlled gas injection system that permits uninterrupted operation for 10–20 h (7–10 million pulses).