It is often desirable to efficiently couple laser foci that are dimensionally large to dimensionally small optical fibers. The underlayer is deposited in a gas atmosphere containing argon and at least one of krypton and xenon in an amount sufficient to reduce the argon remaining in the underlayer to less than 1,000 ppm. The refrigerator comprises a casing in which the compressor and a motor for driving the compressor are accommodated and the refrigerant flows, a stator winding of the motor made of an aluminum wire, and a brine cooled by the refrigerant which is compressed in the casing and then evaporated in the evaporator. More specifically such printer may use a non-continuous ink jet printing assembly such as a drop on demand printing assembly.