JPS6025916B2 - solid state laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state laser device configured to modulate light intensity, and particularly to a four-type solid-state laser device.

FIG. 1 is a conceptual diagram showing the configuration of a conventional solid-state laser device having an optical modulator, in which 1 is a light emitting diode, 2 is a condensing lens, 3 is an optical resonator, and both end faces of a laser active material 4 have a predetermined curvature. A reflective film 5 that is formed on a spherical surface and reflects 100% of the generated laser light, and a reflective film 6 that has a reflectance of 90 to 97%.
is coated with.

Reference numeral 7 denotes a polarizer, 8 an optical modulator made of a material having an electro-optic effect such as LITa03 crystal, and 9 an analyzer, which are arranged so that the polarization direction is orthogonal to the polarizer 7.

In the device configured in this way, the laser active material 4 is excited by the light from the light emitting diode 1 to generate laser light, and the laser light passes through the reflective film 6 and enters the polarizer 7, where it is linearly polarized and converted into light. The amount of light entering the modulator 8 and passing therethrough is modulated according to a signal voltage applied to an electrode provided on the optical modulator 8, and is emitted as a modulated laser light through an analyzer 9.

In conventional laser devices, the optical resonator 3, the polarizer 7, the optical modulator 8, and the analyzer 9 are each formed as separate elements, and the adjustment of these elements is required to be highly accurate. This required a precise support mechanism and precise adjustment work. Furthermore, since a polarizer 7 and an analyzer 9 are required, there is also a drawback that transmission loss is large.

The purpose of this invention is to eliminate the drawbacks of the conventional laser device described above, and the shape of the reflecting surface of the optical resonator 3 is made flat,
Furthermore, the optical resonator 3, the optical modulator 8, and other structurally necessary elements are integrally formed, thereby realizing miniaturization and ease of handling.

An embodiment of this invention will be described below.

FIG. 2 is a sectional view showing a schematic configuration of an embodiment of the present invention, in which reference numeral 10 denotes a parallel plate-like east focusing optical lens, and the end surface on which the light of the light emitting diode 1 enters is coated with a reflective film 5. , the other end face is in plane contact with the NdF50,4 crystal, the other face of the NdF50,4 crystal 4 is coated with a reflective film 6, and the east focusing lens 10, the NdF50,4 crystal 4, and the reflective film are coated. 6 are fixed together with a synthetic resin 11 to form an optical resonator 3.

An optical modulator 8 and an analyzer 9 are further coaxially connected to this optical resonator 3.
are fixed together with synthetic resin 12. With this configuration, the reflective films 5 and 6 can be formed into a flat shape due to the action of the east-focusing lens 10, so each horizontal element can be formed into a flat surface, and therefore, it is possible to have a configuration in which they are integrally fixed with synthetic resin. Furthermore, when NdP50,4 crystal is used as the laser active material, the transmitted laser light is polarized in a specific direction depending on the orientation of the NdP50,4 crystal.

For example, when the b-plate of the N ships 50, 4 is used, the laser beam is polarized in the c-axis direction within the plane of the b-plate. Therefore, the direction that forms an angle of 45° to both the c-axis and the x-axis of the LITa03 crystal forming the optical modulator 8 and the c-axis direction included in the plane of the b-plate of the N-50,4 crystal 4 are made to match. Furthermore, if the analyzer 9 is arranged so that the direction of the polarization vector of the analyzer 9 is orthogonal to the c-axis included in the plane of the b-plate of the NdP50. The passing laser light is modulated by the signal voltage applied to the electrodes, and the polarizer 7 of the conventional device can be omitted.

In the above embodiment, the reflective film 6 is made of N fertilizer 50,4 crystal 4.
An example in which the output surface of the optical modulator 8 is coated is shown.
Structure of coating on the end face of or 100 m thick
A structure may also be adopted in which a coated quartz plate that has been optically polished to a certain degree can be inserted.

Further, the optical modulator 8 has Sro. 258 too. 75Nb206
Needless to say, the crystals are applied to the scales. In this invention, by applying the east-focusing lens 10, all of the joint surfaces of the respective parts constituting the device can be formed into flat surfaces, so that the optical resonator and the optical modulator can be All elements including the laser beam can be constructed as one, and by applying N-50,4 crystal to the laser active material that constitutes the optical resonator, the output laser light can be made to have a certain polarization. Therefore, one polarizing element required in the secondary device can be omitted, and transmission loss can be reduced.

Furthermore, the optical resonator of the device according to the present invention is configured to take out light directly from the crystal side, so it is a so-called hemispherical resonator, and it is possible to obtain coherent light with a small beam divergence angle. It also has the advantage that it can be coupled to a small-area propagation system like an optical fiber with extremely high coupling efficiency. A brief explanation of the drawing. FIG. 1 is a schematic configuration diagram of a solid-state laser device having a conventional optical modulator, and FIG. 2 is a schematic sectional view showing the configuration of an embodiment of the present invention.

In the figure, 1 is a light emitting element, 2 is a lens, 3 is an optical resonator,
5 and 6 are reflective films, 7 is a polarizer, 8 is a light modulator, 9 is an analyzer, and 11 and 12 are synthetic resins.

Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A converging optical lens whose both ends are flat, an NdP_5O_1_4 crystal which faces one end face of this lens, and which faces each of this outer end face and an outer end face of the above-mentioned convergent optical lens, an optical resonator composed of two reflective films each having a predetermined reflectance with respect to excited laser light, and an optical modulator that interfaces with the NdP_5O_1_4 crystal of this optical resonator via one of the reflective films. and an analyzer facing the other surface of the optical modulator and disposed so as to have a polarization angle of a predetermined angle with respect to the polarization direction of the laser beam emitted from the optical resonator, , a fixed laser device in which an optical modulator and a polarizer are fixed together with a synthetic resin having a predetermined refractive index. 2. The solid-state laser device according to claim 1, wherein one of the reflective films is coated on the outer surface of the NdP_5O_1_4 crystal. 3. The solid-state laser device according to claim 1, wherein one of the reflective films is coated on the laser beam incident side end face of the optical modulator. 4. The solid-state laser device according to claim 1, characterized in that a reflective film is coated on one surface of a thin quartz plate which has been optically polished, and the thin quartz plate can be inserted between the NdP_5O_1_4 crystal and the optical modulator.