JPS6057695A - Polarizing control type light source and polarizing controlling device - Google Patents

Abstract

PURPOSE:To facilitate control of the deflecting direction of the optical axis of outgoing light emitted from a semiconductor laser element and to prevent the laser resonator, etc., from being deteriorated by a method wherein a spherical magnetooptic effect plate is used as a window material for a cap, with which the semiconductor laser element is airtightly sealed. CONSTITUTION:A polarizing control type light source, which is used for optical communication, optical information processing, optical sensors, etc., is constituted of a cap 2 for airtight sealing with a built-in semiconductor laser element 1, an Sm-Co magnet 9, a Glan-Thompson prism 10 and an SELFOC lens 11. As a window material for photo emission for the cap 2, with which the semiconductor laser element 1 is airtightly sealed, is used one constituted of optical element 7 having a beam conversional function and a magnetooptic effect plate 13. The optical element 7 shall be spherical for making into such a way that the deflecting direction of the optical axis of outgoing light emitted from the laser element 1 can be easily controlled by a magnet 9. By such a constitution, the deflection of the outgoing optical axis is controlled and deterioration of the laser resonator, etc., is prevented.

Description

[Detailed Description of the Invention] Industrial Fields of Application The present invention is used in optical communications, optical information processing, optical sensors, etc.
This invention relates to a polarization control device using a lJml light source.

Conventional configuration and its problems When converting a semiconductor laser into a device, it is necessary to prevent the deterioration of the resonance H: For the purpose of ensuring safety, the electrode 5 is generally hermetically sealed with a cap 2 containing a window material made of sapphire glass 3 or the like coated with a fouling prevention film 4.
, 6 are removed using a metal seal. In this case, the hermetic sealing cap made of a window material such as sapphire glass 3 has only the role of emitting a small amount of light from the semiconductor laser 1 to the outside of the hermetic sealing cap 2.

1:1 aspect of the invention According to the present invention, a magneto-optic effect plate is used as the window material of the hermetic sealing cap of the semiconductor laser chip, and the polarization direction of the emitted light from the semi-quadram laser element can be easily controlled. The purpose is to obtain a light source that can control polarization.

Structure of the Invention The present invention includes a semiconductor laser element and an airtight sealing cap using a magneto-optical effect plate as a window material of the airtight sealing cap. Further, the present invention is constructed by adding an optical element having a beam conversion function to the above-mentioned configuration.

Optical elements with beam conversion functions include ball lenses, refractive index distribution, and! ! It is a type of lens such as a 1-reel lens, hemispherical lens, or cylindrical lens that has a 0-hime conversion function.

DESCRIPTION OF EMBODIMENTS A first embodiment of the configuration of a polarization-controlled light source of the present invention is shown in FIG. In the present invention, the window material of the hermetic sealing cap of the half-duplex laser is changed to a magneto-optic effect plate.

The magneto-optical effect plate 13 used as a window material for the hermetically sealed soil cap is made of a material having a magneto-optic effect such as (dominant garnet, II-■) semiconductor, paramagnetic material or glass. When absorption in a band is used as a light source, it has the property of rotating the polarization direction of light passing through it by applying a magnetic field, and the rotation angle θ is determined by the strength of the magnetic field H2 Magneto-optic effect plate It can be expressed as θ-RHV using the optical path length a in the center and a constant a (Berve constant v) specific to the magneto-optic effect plate.

The light emitted from the semiconductor laser element 1 is emitted to the outside of the hermetically sealed camp through the window of the hermetically sealed cap.
At this time, when a magnetic field is applied from the outside, the direction of the l1iii wave is rotated by the strength of the magnetic field and the optical path length in the magneto-optic effect plate, and is emitted to the outside of the airtight cap.

A fouling prevention film 4 is applied to the magneto-optic effect plate 13 to prevent fouling.

As a second embodiment, the magneto-optic effect plate 13 is made spherical in order to add the function of condensing the emitted light from the laser element to the (Iiif light control type light source) of the present invention, as shown in FIG. show.

As a third embodiment, polarized light fljIJ of the present invention
In order to provide a light focusing effect to the l1lil type light source, an optical element 7 having a beam conversion function 1 is used in the window material of the hermetically sealed earth cap 2 together with a magneto-optic effect plate 13, as shown in FIG. Optical effect plate 13 and beam conversion function 7:
An optical element with a refractive index of 11 is an example of an optical element with a refractive index of 11.
It is close to both the optical effect plate 13 and the optical element having the beam conversion function, and is bonded using an adhesive that has little absorption at the wavelength used, but the 1 m method may also be used. For example, it is glass for hermetic sealing.

As a fourth implementation 1j, without using the beam eccentricity in the third implementation described above for the full window of the optical element 7 for E-T,
FIG. 4 shows the entire structure placed between the semiconductor laser element 1 in the airtight cover 1 and the window formed by the magneto-optic effect plate 13.

FIG. 5, which is a fifth embodiment, shows a material using a material with a small rotation angle per unit optical path length per unit magnetic field as a magneto-optical effect plate, for example a paramagnetic Faraday glass. This uses a configuration in which the rotation angle of the polarization direction is increased by increasing the length.

The light emitting window of the hermetic sealing cap 2 is tilted with respect to the light emitting surface of the semiconductor laser element 1, and the antireflection films 4a, +b and the total reflection film are applied to the magneto-optic effect plate 13 of the window of the hermetic sealing cap 2. 8 Complete formation. In this configuration, from the semiconductor laser element 1 to ili! , ## The light 9a completely passes through the anti-reflection film 4d, enters the magneto-optic effect plate 13, is reflected by the anti-reflection film 8 on one end face, and passes through the inside of the magneto-optic effect plate 13.
After that, all the end faces of the magneto-optic effect plate 13 will be covered in the same way! R+IS
′! The outgoing light 9b passes through the anti-reflection film 4b on the Miii surface on the outgoing side of the magneto-optic effect plate 13 and is emitted to the outside of the gas bath sealing cap 2.

Note that the total reflection of lf+Ai lfi'l of the magneto-optic effect plate 13] pattern 8 may be attached directly to the magneto-optic effect plate 13; Steam X
Other methods may be used to prevent the light from being totally reflected, such as bonding the total reflection sample 11ilJ in contact with the magneto-optic effect plate 13.

As a sixth embodiment, the uninvented 1llj light control fI11j
The configuration of a light source with an optical isolator for optical communication is shown in No. 6+A as an example of a polarization side leg device using a type optical module. An optical isolator is an optical isolator because the light emitted from the semiconductor laser element is reflected in the middle of the transmission circuit and returns to the semiconductor laser element, making the operation of the semiconductor laser element unstable. In order to completely prevent this, the device allows the J'' sub-light from the semiconductor laser element to pass through, but prevents the light from returning to the semiconductor laser element. As an example, magnetic garnet was used here as the magneto-optic effect plate 13 of the light exit window of the hermetic sealing cap 2 of the semiconductor laser device 1. Magnetic garnet is a ferrimagnetic material, and above a certain strength, even if the magnetic strength is increased, the rotation angle of the polarization direction per length of light D' remains constant at a saturation magnetic field. have The thickness of the magnetic garnet used for the light exit window 3 is such that
The thickness is set so that one component direction of light that enters vertically when I'j is rotated by 45 degrees. Nine cylindrical Sm-Co 11 stones are arranged to surround the light exit window, and a magnetic field is applied to the magnetic garnet 13 surrounding the light exit window.

And 11 opposite to the semiconductor laser element arrangement of the light exit window!
In II, the Glan-Thompson prism 10 with anti-repulsion mechanism is located at a position 46° from the polarization direction of the light immediately after being emitted from the semiconductor laser element, that is, the light that has passed through the light exit window passes through it. Place it in the desired position. Polarization of Glan-Thompson prism 10: l1ll Opposite to type XI light source a1.
j'+6i of Grant Thompson prism 1ltll to jU
] A fiber collimator consisting of a SELFOC lens 11 coated with an antireflection film 4 and a fiber 12 is arranged at 1ii.

The light emitted from the semiconductor laser element is collimated by the hemispherical lens 7 and passes through 13 magnetic garnets.
The i-wave is rotated by 45° in the direction of the i-wave, passes through a Clantomnon prism 10, is focused by a Selfoc lens 11, and is connected to an optical fiber 12.

On the other hand, the reflected light returning to the semiconductor laser element 1 is collimated by the SELFOC lens 11, and the polarization plane is 45 degrees from the 1''-4.1 light from the semiconductor laser element 1. Only the returning light can pass through the Clan-Thompson prism 1o i , +, +fl, and when it passes through the firefly, it is further 45 degrees due to the non-reciprocity of the magnetic 1/1-gain. , Tsuguri Deq
] The polarization direction is rotated by 900 relative to the previous one. Even if some light enters the semiconductor laser element 1 due to the hemispherical lens 7, the polarization direction returns to the output light and the light is directed directly, so the returned light makes the operation of the semiconductor laser element 1 unstable. To do d: None. For example, the light source with an optical isolator for optical communication shown here is not limited to use for optical communication.
ilj (The structure of the 11-inch light source is not limited to the typical one,
Furthermore, the magneto-optic effect plate is not limited to magnetic garnet. In addition, the Sm-Co magnet, Glantomon prism, and fiber collimator do not need to be those shown in the example, as long as they provide the same function, and the structure of the isolator is also limited to those shown in the example. do not have.

The seventh embodiment, polarization flr! As an example of reinstalling the I-Misaki device, FIG. 7 shows an 11°9 configuration of a magneto-optical switch.

Using the polarization-controlled light source taken up as the third embodiment, a Glan-Thompson prism 10 is placed outside the small interest window at a position 90° with respect to the polarization direction of the output light of the semiconductor laser device 1. The magneto-optic effect plate 13 of the polarization control type light source uses magnetic garnet as a row, and j! The polarization direction is rotated by 90 degrees under the magnetic field. ? , make it. Outside 7XLs
When no saturation magnetic field is applied from the semiconductor laser element 1, the light emitted from the semiconductor laser element 1 is focused by the hemispherical lens 7 and exits from the light exit window, but the direction of polarization is perpendicular to the Glan-Thompson prism 10 and passes through. I can't. On the other hand, outside i71! Cal
-) 111 magnetic field x
When the outgoing light from the Glan-Thompson prism 10 passes through the magnetic garnet 13 of the light exit window, the polarization direction is transmitted 90° Il times. It is possible to pass. Other methods such as vapor deposition on a magneto-optical effect plate may be used for the polarizer (not limited to the Clan-Thompson prism 10, but also a dielectric multilayer).

Effects of the Invention By using the 11n1 optical type tfflI light source of the present invention, it is possible to prevent the deterioration of the mirror surface -rj of the semiconductor laser device, reduce the optical irradiance (t11), and reduce the output from the semiconductor laser device. It becomes easy to control the polarization direction of the side light, and furthermore, the +'R configuration of the l-1: polarization i17υ control device becomes easy.

[Brief explanation of the drawing]

Fig. 1 shows the external appearance and internal groove formation 1/J of a semiconductor laser device with a hermetic sealing cap, and Figs. 2 to 5 show the internal h1η formation (
Δ, Fig. 6 is an internal configuration diagram of a light source with an optical isolator as a series of d''; It is an internal configuration diagram of the switch. 1... Semiconductor laser element, 2... Airtight sealing cap, 7... Optical element for what beam conversion function, 9... Sm-Co magnet, 10--Glan-Thompson prism, 11--Selfoc lens, 12--optical fiber, 13--magneto-optic effect plate. Name of one person Patent attorney Toshio Nakao and one other person Figure 1 Figure 2 Figure 4 Figure 3 Figure 6 Figure 7

Claims (4)

[Claims] (1) A polarization-controlled light source characterized in that a magneto-optic effect plate is used as a window material for a hermetically sealed camp for a semiconductor laser device. (2) A polarization-controlled light source according to claim 1, characterized in that a spherical magneto-optic effect plate is used as the window. (3) A polarization control type light source characterized in that a magneto-optic effect plate and an optical element having a beam conversion function are used as a window material of a cap for hermetically sealing a semiconductor laser element. (4) A polarization-controlled light source, a magnetic field generation source for magnetizing the magneto-optic effect of the polarization-controlled light source, a polarization separation function, a beam conversion function, A polarization control device characterized by using a gold optical element having a light source wave function.