JPH0287692A - Semiconductor optical element - Google Patents

Abstract

PURPOSE:To change an effective refraction factor and internal loss and to enable change of oscillation wavelength and oscillation position by forming a plurality of gain waveguide paths close to each other and by changing a current to supply to each electrode. CONSTITUTION:An example of distribution feedback gain waveguide laser having three stripe electrodes is taken. Currents supplied to the three electrodes 1 are named I1, I2, and I3, respectively. Since these upper electrodes 1 are formed close to each other and the waveguide path is a gain waveguide type, a current I2 is injected to a middle electrode 1 at first for laser oscillation. An effective waveguide path width can be changed by injecting a current to electrodes I1 and I3 on the right and the left of the middle electrode I. Therefore, oscillation wavelength can be changed by thus changing an effective refraction factor and an oscillator loss. A light emission position can be made under the electrode I2 by letting I1=I3 and can be deflected right and left from the center by changing the size of I1 and I3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor optical device, and particularly to a method for controlling the oscillation wavelength of a semiconductor laser.

[Conventional technology]

Figure 2 (al, (bl) shows the structure of the end face of a conventional distributed feedback (DFB) type twin stripe laser shown in Abride Physics Lasers, Vol. 48, p. 1725 (1986), and its A. -A or BB sectional view is shown. In the figure, 1 is an upper electrode, 2 is a p-type InGa
AsPD contact layer, 3 is p type! nP cladding layer, 4 is p-type 1 nGaAs P anti-meltback layer, 5 is undoped InGaAsP active layer, 6 is n-type InGaAs
A P waveguide layer, 7 an n-type InP substrate, 8 a lower electrode, 9 an insulating layer, and 10 an Fe-doped semi-insulating rnP buried layer.

Next, the operation will be explained.

The two waveguides A and B of the present distributed feedback (DFB) laser have different widths, so that the effective refractive index n e f f
will also have different values. Here, when the period of the diffraction grating is 8, the oscillation wavelength is approximately given by λ=2nerrΔ/m (m: integer).

Therefore, since n@ff is different, laser beams of different wavelengths can be obtained from the two waveguides.

[Problem to be solved by the invention]

Since the conventional distributed feedback laser device has a built-in refractive index guide type waveguide as described above, the oscillation position is fixed.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a semiconductor optical device in which the oscillation wavelength and oscillation position can be arbitrarily controlled.

[Means to solve the problem]

In the semiconductor optical device according to the present invention, the laser waveguide is of a gain guide type, and a plurality of stripe electrodes are arranged in close proximity to each other.

[Effect]

In this invention, since there is no built-in waveguide, the effective waveguide width can be changed by changing the method of current injection.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, consider a distributed feedback gain waveguide laser having three stripe electrodes. Here, it is assumed that the currents flowing through the three electrodes 1 are rl and Iz+rl, respectively.

These upper electrodes 1 are formed close to each other, and since the waveguide is a gain waveguide type, the current is first applied to the central electrode 1.
2 is injected to cause laser oscillation, and by injecting currents 1 and 2 to the left and right electrodes, the effective waveguide width can be changed. Therefore, by changing the effective refractive index and cavity loss, it is possible to change the oscillation wavelength.

At this time, the light emitting position is set to I, -13, so that it is under the I2 electrode, and 11! By changing the size of , you can move left and right from the center.

〔Effect of the invention〕

As described above, according to the present invention, a plurality of gain waveguides are formed close to each other in a semiconductor optical device having a distributed feedback structure, so that the effective refractive index can be changed by changing the current flowing through each electrode. It has the effect of changing the oscillation wavelength and oscillation position by changing the internal loss.

[Brief explanation of drawings]

FIG. 1 shows an end face of a laser according to an embodiment of the present invention, FIG. 2(a) shows an end face of a conventional distributed feedback twin stripe laser, and FIG. 2(b) shows an A- A,
Or it is a BB sectional view. 1 is an upper electrode, 2 is a p-type 1nGaAsP:2 contact layer, 3 is a p-type InP cladding layer, 4 is a p-type InGaAsP
Anti-meltback layer, 5 is undoped InGaAsP
The active layer is an n-type InGaAsP waveguide layer 6, an n-type InP substrate 7, a lower electrode 8, an insulating layer 9, and an Fe-doped semi-insulating InP buried layer 10. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 2 (Q) Figure 2 (b)

Claims (1)

[Claims] (1) A semiconductor characterized in that, in a laser diode with a distributed feedback structure and a plurality of gain waveguides formed closely together, the oscillation wavelength is controlled by changing the current level injected into each waveguide. optical element.