US 11,658,464 B2
Semiconductor optical amplifier
Junichiro Hayakawa, Kanagawa (JP); Daiki Tominaga, Kanagawa (JP); and Akemi Murakami, Kanagawa (JP)
Assigned to FUJIFILM Business Innovation Corp., Tokyo (JP)
Filed by FUJIFILM Business Innovation Corp., Tokyo (JP)
Filed on Aug. 7, 2019, as Appl. No. 16/535,031.
Claims priority of application No. JP2018-152745 (JP), filed on Aug. 14, 2018.
Prior Publication US 2020/0059070 A1, Feb. 20, 2020
Int. Cl. H01S 5/10 (2021.01); H01S 5/183 (2006.01); H01S 5/026 (2006.01); H01S 5/343 (2006.01); H01S 5/50 (2006.01); H01S 5/125 (2006.01)
CPC H01S 5/18311 (2013.01) [H01S 5/026 (2013.01); H01S 5/1003 (2013.01); H01S 5/125 (2013.01); H01S 5/18344 (2013.01); H01S 5/34353 (2013.01); H01S 5/50 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A semiconductor optical amplifier comprising:
a conductive region that is provided on a substrate and allows light transmission; and
a nonconductive region that is provided around the conductive region and prohibits light transmission,
wherein the conductive region includes
a first region including a light-coupling portion to which light from an external light-source unit is coupled; and
a second region having a narrower width than the first region and connected to the first region through a connecting portion, the second region including a light-amplifying portion amplifying the light from the light-coupling portion by propagating the light in a predetermined propagating direction along a surface of the substrate, the light-amplifying portion outputting the amplified light in a direction intersecting the surface of the substrate,
wherein, seen in a direction perpendicular to the surface of the substrate, the semiconductor optical amplifier includes a portion where a width of the conductive region is continuously reduced from the first region to the second region,
wherein the conductive region has a curved outline segment in the connecting portion, and the curved outline segment has a curvature radius of 20 μm or greater and 55 μm or smaller.