Patent ID: 7839912

Claim:
A surface emitting laser comprising: a resonator; a first reflector; and a second reflector, wherein the resonator and the first and second reflectors are provided on a substrate, wherein the resonator includes an active region and a current confinement region, wherein the resonator includes a first refractive index region that is located at a central portion of the resonator and a second refractive index region that is located at a peripheral portion of the resonator and that is lower than the first refractive index region in effective refractive index, wherein a resonator length I 1 of a first region of the resonator that includes the first refractive index region causes the first region of the resonator to satisfy a resonance condition, and a resonator length I 2 of a second region of the resonator that includes the second refractive index region causes the second region of the resonator not to satisfy the resonance condition, wherein the first refractive index region is equal in physical length to that of the second refractive index region, and wherein the resonator length I 1 of the region including the first refractive index region and the resonator length I 2 of the region including the second refractive index region satisfy the following conditional expressions: I 1 =I 2 , I 1 =Nλ/( 2 n h ), I 2 =( N− 1)λ/2 n h +λ/4 n l , and n h >n l , in which N is an integer equal to or larger than two, where λ indicates an oscillation wavelength, n h indicates an effective refractive index of a fundamental mode selection region, and n l indicates an effective refractive index of a high-order mode oscillation suppression region.