A dual chamber gas discharge laser light source, comprising: a master oscillator having a laser chamber containing a lasing medium gas comprising a halogen; an amplifier having a laser chamber containing a lasing medium gas comprising a halogen; a gas optimization system including a controller automatically executing an optimization scheme after a refill of the gas in the amplifier laser chamber, the optimization scheme comprising: a first sequence (201, 301-307) in which the laser is fired in continuous mode at a first pulse rate and a target energy while measuring the discharge voltage of the dual chamber gas discharge laser light source, and, if the discharge voltage is below a predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; a second sequence (202, 401-407) in which the laser is fired in continuous mode at a second higher pulse rate and the target energy while measuring the discharge voltage, and, if the discharge voltage is below the predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; and a third sequence in which the laser is fired in bursts of pulses at the target energy while measuring the discharge voltage and master oscillator output energy, and, if the discharge voltage is below the predetermined minimum value (Vmin), or the master oscillator output energy is below another predetermined minimum value (Emin), bleeding gas from the amplifier chamber until both the discharge voltage and the master oscillator output energy are equal to or greater than the respective predetermined minimum values. a master oscillator having a laser chamber containing a lasing medium gas comprising a halogen; an amplifier having a laser chamber containing a lasing medium gas comprising a halogen; a gas optimization system including a controller automatically executing an optimization scheme after a refill of the gas in the amplifier laser chamber, the optimization scheme comprising: a first sequence (201, 301-307) in which the laser is fired in continuous mode at a first pulse rate and a target energy while measuring the discharge voltage of the dual chamber gas discharge laser light source, and, if the discharge voltage is below a predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; a second sequence (202, 401-407) in which the laser is fired in continuous mode at a second higher pulse rate and the target energy while measuring the discharge voltage, and, if the discharge voltage is below the predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; and a third sequence in which the laser is fired in bursts of pulses at the target energy while measuring the discharge voltage and master oscillator output energy, and, if the discharge voltage is below the predetermined minimum value (Vmin), or the master oscillator output energy is below another predetermined minimum value (Emin), bleeding gas from the amplifier chamber until both the discharge voltage and the master oscillator output energy are equal to or greater than the respective predetermined minimum values. a first sequence (201, 301-307) in which the laser is fired in continuous mode at a first pulse rate and a target energy while measuring the discharge voltage of the dual chamber gas discharge laser light source, and, if the discharge voltage is below a predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; a second sequence (202, 401-407) in which the laser is fired in continuous mode at a second higher pulse rate and the target energy while measuring the discharge voltage, and, if the discharge voltage is below the predetermined minimum value (Vmin), bleeding gas from the amplifier chamber until the discharge voltage is equal to or greater than the minimum value; and a third sequence in which the laser is fired in bursts of pulses at the target energy while measuring the discharge voltage and master oscillator output energy, and, if the discharge voltage is below the predetermined minimum value (Vmin), or the master oscillator output energy is below another predetermined minimum value (Emin), bleeding gas from the amplifier chamber until both the discharge voltage and the master oscillator output energy are equal to or greater than the respective predetermined minimum values.