Stepped substrate semiconductor laser for emitting light at slant portion

Claim 2

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing a plane (100) or a plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer laminated on said active layer and having a first p-type impurity concentration at a region along the slant surface and a second p-type impurity concentration, which is lower than said first p-type carrier concentration at said slant region, at a region along the flat surfaces; and a single cladding and blocking layer laminated on said first p-type cladding layer, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and an n-type current blocking layer at a region along the flat surfaces.

Claim 3

A semiconductor laser according to claim 1, further comprising a buffer layer formed on said stepped substrate and having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface exposing a plane near a plane (411)A.

Claim 4

A semiconductor laser according to claim 1, wherein said cladding and blocking layer is doped alternately with an n-type impurity S and a p-type impurity Zn or Cd.

Claim 5

A semiconductor laser according to claim 1, wherein said cladding and blocking layer is doped at the same time with an n-type impurity S and a p-type impurity Zn or Cd.

Claim 6

A semiconductor laser according to claim 1, wherein said cladding and blocking layer includes p-type thin layer and n-type thin layer alternately laminated two periods or more on said first p-type cladding layer, said p-type thin layer having a high p-type impurity concentration at a region along the slant surface and a low p-type impurity concentration at a region along the flat surfaces, and said n-type thin layer having a low n-type impurity concentration at a region along the slant surface and a high n-type impurity concentration at a region along the flat surfaces.

Claim 7

A semiconductor laser according to claim 1, wherein said cladding and blocking layer laminated on said first p-type cladding layer has a high p-type impurity concentration and a low S concentration at a region along the slant surface and a low p-type impurity concentration and a high S concentration at a region along the flat surfaces, said p-type impurity being Zn or Cd, S and Zn or Cd being doped at the same time, and forms said second p-type cladding layer at a region along the slant surface and said n-type current layer at a region along said flat surfaces.

Claim 8

A semiconductor laser according to claim 1, wherein said cladding and blocking layer laminated on said first p-type cladding layer and forming said n-type current blocking layer has a thickness in the range from about 0.15 to 0.35 μm at a region along the flat surfaces.

Claim 9

A semiconductor laser according to claim 1, wherein said first p-type cladding layer laminated on said active layer has a thickness in the range from about 0.15 to 0.35 μm at a region along the flat surfaces.

Claim 12

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing the plane (100) or the plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer formed on said stepped substrate and having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer formed on said active layer and having a high p-type impurity concentration at a region along the slant surface and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer formed on said first p-type cladding layer, having a high p-type impurity concentration and a low S concentration at a region along the slant surface and a low p-type impurity concentration and a high S concentration at a region along the flat surfaces, said p-type impurity being Zn or Cd, S and Zn or Cd being doped at the same time, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and said n-type current layer at a region along said flat surfaces.

Claim 13

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing the plane (100) or the plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer formed on said stepped substrate and having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer formed on said active layer and having a high p-type impurity concentration at a region along the slant surface and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer formed on said first p-type cladding layer, having a high p-type impurity concentration and a low S concentration at a region along the slant surface and a low p-type impurity concentration and a high S concentration at a region along the flat surfaces, said p-type impurity being Zn or Cd, S and Zn or Cd being doped at the same time, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and said n-type current layer at a region along said flat surfaces.

Claim 14

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing a plane (100) or a plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer laminated on said active layer and having a high p-type impurity concentration at a region along the slant surface and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer laminated on said first p-type cladding layer, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and an n-type current blocking layer having a thickness in the range from about 0.15 to 0.35 μm at a region along the flat surfaces.

Claim 15

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing a plane (100) or a plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer laminated on said active layer and having a high p-type impurity concentration at a region along the slant surface and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer laminated on said first p-type cladding layer, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and an n-type current blocking layer having a thickness in the range from about 0.15 to 0.35 μm at a region along the flat surfaces.

Claim 16

A semiconductor laser according to claim 11, wherein said cladding and blocking layer is doped alternately with an n-type impurity S and a p-type impurity Zn or Cd.

Claim 17

A semiconductor laser according to claim 11, wherein said cladding and blocking layer is doped at the same time with an n-type impurity S and a p-type impurity Zn or Cd.

Claim 18

A semiconductor laser according to claim 11, further comprising a third p-type cladding layer formed on said cladding and blocking layer.

Claim 19

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing a plane (100) or a plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer laminated on said active layer and having a high p-type impurity concentration at a region along the slant surface and a thickness in the range from about 0.15 to 0.35 μm and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer laminated on said first p-type cladding layer, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and an n-type current blocking layer at a region along the flat surfaces.

Claim 20

A semiconductor laser comprising: a stepped substrate of group III-V compound semiconductor having two flat surfaces exposing a plane (100) or a plane (n11)A (n being a real number, 7<n) and a slant surface exposing a plane (m11)A (m being a real number, 2≦m≦7) and interconnecting the two flat surfaces; an active layer having two flat surfaces exposing a plane (100) or a plane (n11)A and a slant surface having a width of 2.5 μm or less and exposing a plane (k11)A (k being a real number, 3≦k≦7), the slant surface of the active layer interconnecting the two flat surfaces of the active layer; a first p-type cladding layer laminated on said active layer and having a high p-type impurity concentration at a region along the slant surface and a thickness in the range from about 0.15 to 0.35 μm and a low p-type impurity concentration at a region along the flat surfaces; and a single cladding and blocking layer laminated on said first p-type cladding layer, said single cladding and blocking layer forming a second p-type cladding layer at a region along the slant surface and an n-type current blocking layer at a region along the flat surfaces.

Claim 21

A semiconductor laser according to claim 15, wherein said first p-type cladding layer is doped with Zn.

Claim 22

A semiconductor laser according to claim 15, further comprising a third p-type cladding layer formed on said cladding and blocking layer.

Claim 23

A semiconductor laser according to claim 17, wherein said third p-type cladding layer has a thickness of about 1.5 μm or more.