JPS62186210A - Semiconductor laser module - Google Patents

Abstract

PURPOSE:To obtain a semiconductor laser module with high output which is allowed to converge laser light projected from two light emitting points into one point by constituting the semiconductor laser module of a semiconductor laser element for emitting light from two points, a 1/2 wavelength plate for rotating the deflecting direction of laser light by 90 deg., a multiple image element for coupling a laser light through the 1/2 wavelength plate with a projected laser light and allowing to converge them into one point, and a condenser lens. CONSTITUTION:One laser light (a) out of respective laser light beams (a), (b) projected from the semiconductor laser element 1 is rotated at its deflecting direction by 90 deg. through the 1/2 wavelength plate 4, so that the deflecting directions of respective laser light beams (a), (b) are vertical to each other. Then, respective laser light beams (a), (b) are made incident on the multiple image element 5 through the 1st condenser lens 2a and coupled with each other as one laser light by double refractive property and the coupled laser light is refracted by the 2nd condenser lens 2b and concentrated into one point on the end surface of an optical fiber 3. Consequently, the semiconductor laser element 1 for emitting laser light beams from two points can be coupled with the optical fiber 3 having thin core diameter.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a semiconductor laser module, particularly the structure of its optical system. A 172-wave plate for rotating the polarization direction of the laser light emitted from the light emitting point by 90 degrees, and the laser light passing through the 1/2 wavelength plate and the laser light emitted from the other light emitting point are combined into a single point. By comprising a double image element and a condensing lens system, the laser light emitted from each of the light emitting points is condensed to one point.

<Conventional technology> The two-point emitting semiconductor laser device is 1. Emit two lasers in parallel to increase output.

2. In optical communications, parallelizing two lasers to improve reliability.

3. In optical communications, two lasers with different wavelengths are emitted in parallel for wavelength multiplexing communications.

It has been developed for such purposes. When coupling this two-point emitting semiconductor laser element to an optical fiber, conventionally, the second
As shown in the figure, laser light emitted from two light emitting points A and B of a two-point light emitting semiconductor laser element 1 was condensed by a convex lens 2 and entered into an optical fiber 3.

<Problems to be Solved by the Invention> However, in the optical system as described above, the laser beam is not focused on one point at the end face of the optical fiber 3, but forms images of two points. Therefore, when the core diameter of the optical fiber 3 is small, it is not possible to make both laser beams enter the optical fiber 3.

An object of the present invention is to provide a semiconductor laser module that can solve the above problems.

<Means for Solving the Problems> The present invention comprises a two-point emitting semiconductor laser device, a 172-wave plate for rotating the deflection direction of laser light emitted from one of the light emitting points by 90 degrees, and It is composed of a double image element and a condensing lens for combining the laser light that has passed through the 172-wavelength plate and the laser light emitted from the light emitting point of the lens and condensing the light into one point.

<Function> With the above configuration, one of the laser beams emitted from each light-emitting point is deflected by the phase plate, and then the two laser beams are refracted and combined by the double image element and focused at one point. be illuminated.

<Example> Embodiments of the present invention will be described in detail below with reference to the drawings.

The semiconductor laser module shown in FIG. 1 consists of a two-point emitting semiconductor laser element [172-wavelength plate 4.1 for rotating the deflection direction of laser light a from one light-emitting point A by 90°; Laser light a and other light emitting points B
A first condensing lens 2a such as a convex lens for guiding the laser beam emitted from the laser beam to a double image element to be described later, and a double image element such as a Wollaston prism for refracting and combining the respective laser beams a and b. 5. A second condensing lens 2b such as a convex lens for condensing each laser beam a and b to a single point at the end face of the optical fiber 3
It consists of.

With the above configuration, each of the laser beams a and b emitted from the semiconductor laser element l has one of the laser beams ah<
The deflection direction is rotated by 90 degrees by the 1/2 wavelength plate 4, and the deflection directions of the laser beams a and b are perpendicular to each other. Next, each of the laser beams a and b is first focused.

The laser beams a and b are incident on the double image element 5 through the lens 2a, and due to their birefringence, the laser beams a and b are combined into one laser beam. This laser beam is refracted by the second condensing lens 2b and condensed at one point on the end face of the optical fiber 3.

As a result, in this example, it becomes possible to couple the two-point emitting semiconductor laser element 1 with the optical fiber 3 having a small core diameter.

In addition, in this example, condenser lenses 2 a, 2 are used for condensing light.
Although two lenses b are used, the invention is not limited to this, and other condensing lens systems can also be used.

Further, the present invention can be applied to a so-called semiconductor laser array having two light emitting points in one semiconductor laser chip, or to a semiconductor laser composite element consisting of two semiconductor laser chips.

<Effects of the Invention> As described above, according to the present invention, it is possible to provide a high-output semiconductor laser module that can condense laser light emitted from two light emitting points to one point.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Semiconductor laser element, 2 a, 2 b... Condensing lens, 4... 172 wavelength plate, 5... Double image element.

Claims (1)

[Claims] 1 or 2 point emitting semiconductor laser element, a 1/2 wavelength plate for rotating the polarization direction of the laser beam emitted from one of the emission points by 90 degrees, and a laser beam passing through the 1/2 wavelength plate. and a double image element for combining and condensing the laser beams emitted from the other light emitting points to one point, and a condensing lens system.