Photonic crystal laser and method of manufacturing photonic crystal laser
A photonic crystal laser comprises an n-type substrate, an n-type clad layer, an active layer, a p-type clad layer, a photonic crystal layer, a p-type electrode, an n-type electrode and a package member. The n-type clad layer is formed on a first surface of the n-type substrate. The active layer is formed on the n-type clad layer. The p-type clad layer is formed on the active layer. The photonic crystal layer is formed between the n-type clad layer and the active layer or between the active layer and the p-type clad layer, and includes a photonic crystal portion. The p-type electrode is formed on the photonic crystal portion. The n-type electrode is formed on a second surface, and includes a light-transmitting portion arranged on a position opposed to the photonic crystal portion and an outer peripheral portion having lower light transmittance than the light-transmitting portion.
1. A photonic crystal laser comprising:
a conductive n-type substrate including a first surface and a second surface opposite to said first surface;
an n-type clad layer formed on said first surface of said n-type substrate;
an active layer formed on said n-type clad layer for emitting light;
a p-type clad layer formed on said active layer;
a photonic crystal layer, formed between said n-type clad layer and said active layer or between said active layer and said p-type clad layer, including a photonic crystal portion having a photonic crystal structure, the photonic crystal portion including a high refractive portion and a low refractive portion positioned within the high refractive portion;
a p-type electrode formed on said photonic crystal portion;
an n-type electrode, formed on said second surface of said n-type substrate, including a light-transmitting portion comprising an opening in the n-type electrode arranged on a position opposed to said photonic crystal portion and an outer peripheral portion having lower transmittance of said light than said light-transmitting portion; and
a package member formed on said p-type electrode.
2. The photonic crystal laser according to claim 1 , wherein
a mesa structure is formed on the outer periphery of said p-type electrode, and
an insulating film is formed on at least part of the surface of said mesa structure.
3. The photonic crystal laser according to claim 1 , wherein
said light-transmitting portion includes the whole region defined by projecting said photonic crystal portion on said second surface of said n-type substrate as viewed from the side of said p-type electrode.
4. The photonic crystal laser according to claim 1 , wherein
said light-transmitting portion further includes an electrode provided with uniformly dispersed openings and electrically connected with said outer peripheral portion.
5. The photonic crystal laser according to claim 1 , further comprising a transparent electrode, made of a material transparent with respect to said light, arranged on said light-transmitting portion and electrically connected with said outer peripheral portion of said n-type electrode.
6. The photonic crystal laser according to claim 1 , wherein said n-type substrate is made of gallium nitride.