Semiconductor laser drive circuit, method for driving semiconductor laser drive circuit, distance measuring apparatus, and electronic apparatus
A semiconductor laser drive circuit includes: an anode electrode divided into at least one gain region and at least one light absorption region; a cathode electrode shared between the gain region and the light absorption region; and a resistance connected to the anode electrode of the light absorption region.
1. A semiconductor laser drive circuit, comprising:
an anode electrode divided into at least one gain region and at least one light absorption region;
a cathode electrode shared between the gain region and the light absorption region;
a resistance connected to the anode electrode of the light absorption region;
a delay line having a first terminal directly connected to the anode electrode; and
a first switching element connected between the delay line and a ground or a constant voltage source, wherein
the first switching element is a transistor,
a second terminal of the delay line is directly connected to an emitter of the transistor, and
the ground or the constant voltage source is connected to a collector of the transistor.
2. The semiconductor laser drive circuit according to claim 1 , wherein
the resistance is connected to the ground or an additional constant voltage source.
3. The semiconductor laser drive circuit according to claim 1 ,
wherein a second switching element is connected between the cathode electrode and the ground.
4. The semiconductor laser drive circuit according to claim 3 , wherein
a capacitor is connected between a point of connection between the anode electrode and the resistance, and a point of connection between the cathode electrode and the second switching element.
5. The semiconductor laser drive circuit according to claim 1 , wherein
the light absorption region has a parasitic capacitive component in parallel with a diode.
6. The semiconductor laser drive circuit according to claim 1 , wherein
an output terminal is connected to the anode electrode via a capacitor.
7. A distance measuring apparatus, comprising:
a semiconductor laser device including the semiconductor laser drive circuit according to claim 1 ;
a light reception unit configured to receive light reflected by an object that reflects laser light emitted from the semiconductor laser device; and
an arithmetic unit configured to acquire a distance to the object, based on a basis of a timing of emission and a timing of reception of the laser light.
8. An electronic apparatus including the distance measuring apparatus according to claim 7 .
9. A semiconductor laser drive circuit, comprising:
an anode electrode divided into at least one gain region and at least one light absorption region;
a cathode electrode shared between the gain region and the light absorption region,
a delay line having a first terminal connected to the anode electrode; and
a first switching element connected between the delay line and a ground or a constant voltage source, wherein
the first switching element is a transistor,
a second terminal of the delay line is connected to an emitter of the transistor, and
the ground or the constant voltage source is connected to a collector of the transistor, wherein a second switching element connected between the cathode electrode and the ground is turned on or off, to modulate a laser output.
10. The semiconductor laser drive circuit according to claim 9 , wherein
the second switching element is turned on or off, to modulate an absorption coefficient of the light absorption region to modulate a laser output.
11. The semiconductor laser drive circuit according to claim 10 , wherein
the second switching element is turned on to make the absorption coefficient smaller, and the second switching element is turned off to make the absorption coefficient greater.
12. A method for driving a semiconductor laser drive circuit that includes:
an anode electrode divided into at least one gain region and at least one light absorption region;
a cathode electrode shared between the gain region and the light absorption region;
a delay line having a first terminal connected to the anode electrode; and
a first switching element connected between the delay line and a ground or a constant voltage source, the method comprising:
turning on or off a second switching element connected between the cathode electrode and the ground, to modulate a laser output, wherein
the first switching element is a transistor,
a second terminal of the delay line is connected to an emitter of the transistor, and
the ground or the constant voltage source is connected to a collector of the transistor.