1. A semiconductor optical element comprising an n-type GaAs buffer layer, an n-type AlGaInP cladding layer, a first InGaAsP (including zero As content) guide layer without added dopant impurities, an InGaAsP (including zero In content) active layer, a second InGaAsP (including zero As content) guide layer without added dopant impurities, a p-type AlGaInP cladding layer, a p-type band discontinuity reduction layer, and a p-type GaAs contact layer, sequentially laminated, on an n-type GaAs substrate, wherein one of C and Mg is the dopant impurity in the p-type GaAs contact layer, the p-type band discontinuity reduction layer, and the p-type AlGaInP cladding layer.
2. The semiconductor optical element according to claim 1, wherein C is the dopant impurity for the p-type GaAs contact layer, and Mg is the dopant impurity in the p-type band discontinuity reduction layer and the p-type AlGaInP cladding layer.
3. The semiconductor optical element according to claim 1, wherein C is the dopant impurity in the p-type GaAs contact layer, the p-type band discontinuity reduction layer, and the p-type AlGaInP cladding layer.
4. The semiconductor optical element according to claim 1, wherein Mg is the dopant impurity in the p-type GaAs contact layer, the p-type band discontinuity reduction layer, and the p-type AlGaInP cladding layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A communication device comprising:
determining means for determining whether a data link is released or not when a call is released;
counting means for counting a predetermined time according to the determination of the determining means; and
control means for starting a process for releasing the data link according to a passage of the predetermined time.
2. A communication device according to claim 1, wherein the control means sends a data link releasing request from a layer 3 to a layer 2 after the passage of the predetermined time.
3. A communication device according to claim 1, wherein the control means sends a signal for instructing data link releasing through a line after the passage of the predetermined time.
4. A communication device according to claim 1, wherein when a generated call is detected before the predetermined time is counted by the counting means, the counting by the counting means is stopped.
5. A communication device according to claim 1, wherein the predetermined time can be settable.
6. A communication device according to claim 1, wherein when a signal for instructing data link releasing is received through a network before the predetermined time is counted by the counting means, the data link releasing is notified from a layer 2 to a layer 3.
7. A communication device according to claim 1, wherein the determination by the determining means is executed when a signal for notifying completion of call releasing is sent or received.
8. A communication device according to claim 1, wherein the determining means determines that the data link is released if a data link is being set, and determines that the data link is not released if a data link is not being set.
9. A communication device according to claim 1, wherein the determining means determines that the data link is released if no other calls are present, and determines that the data link is not released if another call is present.
10. A communication device according to claim 1, wherein the determining means determines that the data link is released if there is setting to release the data link from a terminal, and determines that the data link is not released if there is setting not to release the data link from the terminal.
11. A control method for a communication device, comprising:
a determining step for determining whether a data link is released or not when a call is released;
a counting step for counting a predetermined time according to the determination by the determining step; and
a control step for starting a process for releasing the data link according to a passage of the predetermined time.
12. A program for controlling a communication device, comprising:
a determining step for determining whether a data link is released or not when a call is released;
a counting step for counting a predetermined time according to the determination by the determining step; and
a control step for starting a process for releasing the data link according to a passage of the predetermined time.