Patent ID: 7999626

Claim:
A physical section of an atomic oscillator, comprising at least: a gas cell including a cylindrical portion and first and second windows respectively hermetically-closing openings of both sides of the cylindrical portion to form a cavity in which gaseous metal atoms are sealed; a light reflection unit disposed on the first window; a first heating unit disposed to be closely attached to the second window and heating the gas cell at a predetermined temperature; a light source disposed so as to allow a light emitting part thereof to face the light reflecting unit, emitting excitation light exciting the metal atoms in the gas cell, and provided on a side, the side being a reverse side to a side to which the gas cell is provided, of the first heating unit; a light detecting unit detecting the excitation light reflected by the light reflection unit, and provided also on the side, the side being the reverse side to the side to which the gas cell is provided, of the first heating unit; and a Peltier element interposed between the light source and the first heating unit, and between the light detection unit and the first heating unit.