Laser system and electronic device manufacturing method

An electronic device manufacturing method comprising:

• generating laser light with a laser system, the laser system including
• a laser oscillator system configured to output first pulsed laser light in a first polarization direction and second pulsed laser light in a second polarization direction, which is obtained by rotating the first polarization direction by 45 degrees in a first rotation direction,
• a beam combiner configured to couple the first pulsed laser light and the second pulsed laser light such that the first pulsed laser light and the second pulsed laser light are caused to propagate in a common direction, the beam combiner including
• a first polarizer that transmits the first pulsed laser light,
• a first Faraday rotator that rotates a polarization direction of the first pulsed laser light transmitted through the first polarizer by 45 degrees in a second rotation direction that is a direction opposite to the first rotation direction,
• a second polarizer that transmits the first pulsed laser light transmitted through the first Faraday rotator and reflects the second pulsed laser light, and
• a multi-pass Faraday mirror that reflects the first pulsed laser light transmitted through the second polarizer and the second pulsed laser light reflected by the second polarizer towards the second polarizer,
• the multi-pass Faraday mirror including a first Faraday material through which the first pulsed laser light and the second pulsed laser light are transmitted, an electromagnet that applies a magnetic field to the first Faraday material, and a plurality of reflective mirrors that cause the first pulsed laser light and the second pulsed laser light transmitted through the first Faraday material to turn back toward the first Faraday material,
• a power supply configured to cause a current to flow to the electromagnet, and
• a processor configured to control the current flowing to the electromagnet via the power supply such that no current is caused to flow to the electromagnet when the first pulsed laser light is transmitted through the first Faraday material while a current is caused to flow to the electromagnet to rotate a polarization direction of the second pulsed laser light by 90 degrees when the second pulsed laser light is transmitted through the first Faraday material;
• outputting the laser light to an exposure apparatus;
• and
• exposing a photosensitive substrate to the laser light within the exposure apparatus to manufacture an electronic device.