Gas laser with internal gas reservoir having long regeneration path

A gas laser, comprising:

• an inner tube filled with gas and having mirrors at its opposite ends to define a resonant chamber, an outer tube filled with gas and defining a gas reservoir for the gas in the resonant chamber;
• a pair of intermediate tubes coaxial with and between said inner and outer tubes and extending for a major part of the length of said inner and outer tubes;
• one of said intermediate tubes being open at one end facing one end of the laser and joined at its opposite end facing the opposite end of the laser to said outer tube;
• the other of said intermediate tubes being open at its end facing said opposite end of the laser and joined at its end facing said one end of the laser to said inner tube, whereby said pair of intermediate tubes divide the reservoir into a plurality of annular spaces defining a zigzag path between the opposite ends of said inner tube;
• and electrodes for energizing the gas in the resonant chamber.

A gas laser comprising:

• first, second, third, fourth and fifth coaxial tubes of increasing diameters;
• a front partial reflector at one end of said tubes;
• a rear total reflector at the opposite end of said tubes;
• a coolant fluid inlet port communicating with one end of the annular space between said first and second tubes, and an outlet port communicating with the outlet end of said annular space for circulating a coolant fluid in said annular space between said first and second tubes;
• a gas filling the remaining spaces between said tubes to define a resonant chamber within the inner tube, and a gas reservoir in the spaces between said second, third, fourth and fifth tubes;
• and electrodes for exciting the gas within said resonant chamber;
• said third tube being open at one end of the laser and joined to said fifth tube at the opposite end of the laser, and said fourth tube being open at said opposite end of the laser and being joined at said one end of the laser to said second tube, whereby the spaces between the second, third, fourth and fifth tubes define a gas reservoir communicating with each other and with the opposite ends of said first tube in zigzag fashion.