A narrow band molecular fluorine laser system includes an oscillator and an amplifier, wherein the oscillator produces a 157 nm beam having a linewidth less than 1 pm and the amplifier increases the power of the beam above a predetermined amount, such as more than one or several Watts. The oscillator includes a discharge chamber filled with a laser gas including molecular fluorine and a buffer gas, electrodes within the discharge chamber connected to a discharge circuit for energizing the molecular fluorine, and a resonator including the discharge chamber for generating a laser beam having a wavelength around 157 nm. Line-narrowing optics are included intra- and/or extra-resonator for reducing the linewidth of the laser beam to less than 1 pm. The amplifier may be the same or a different discharge chamber, and optical and/or electronic delays may be used for timing pulses from the oscillator to reach the amplifier at a maximum in the discharge current of the amplifier.