公开(公告)号：US12046875B2

公开(公告)日：2024-07-23

申请号：US17313389

申请日：2021-05-06

Applicant: HAMAMATSU PHOTONICS K.K.

Inventor： Kazuue Fujita ,  Masahiro Hitaka ,  Atsushi Sugiyama ,  Kousuke Shibata

IPC: H01S5/34 ,  H01S5/042 ,  H01S5/06 ,  H01S5/30 ,  H01S5/028 ,  H01S5/12 ,  H01S5/22

CPC classification number: H01S5/3401 ,  H01S5/0425 ,  H01S5/0604 ,  H01S5/3086 ,  H01S5/3402 ,  H01S5/0287 ,  H01S5/04257 ,  H01S5/12 ,  H01S5/22 ,  H01S2302/02

Abstract: A quantum cascade laser device includes a semiconductor substrate, an active layer provided on the semiconductor substrate, and an upper clad layer provided on a side of the active layer opposite to the semiconductor substrate side and having a doping concentration of impurities of less than 1×1017 cm−3. Unit laminates included in the active layer each include a first emission upper level, a second emission upper level, and at least one emission lower level in their subband level structure. The active layer is configured to generate light having a center wavelength of 10 μm or more due to electron transition between at least two levels of the first emission upper level, the second emission upper level, and the at least one emission lower level in the light emission layer in each of the unit laminates.