Light source device and projector

A projector comprising:

• a light source device including
• a microwave generating section for generating a microwave,
• a reflector connected to the microwave generating section, and
• a microwave electrodeless lamp disposed inside a cavity, the cavity including the reflector and a chamber covering an opening section of the reflector,
• the chamber including a tube member having an opening section for communicating the inside and the outside of the cavity to lead a light flux out of the chamber, and
• a bore diameter D of the opening section, a length L of the tube member, a wavelength λ of the microwave, and a wavelength Λ of the light flux satisfying Λ<D≦(¼)Λ, L≧(¼)λ, and D+L=(½)λ;
• an optical modulation section for modulating light flux emitted from the light source device in accordance with input image information to form an optical image;
• and
• a projection section for projecting the optical image formed by the optical modulation section.