JPH04134326A - Short wavelength laser beam source and production thereof - Google Patents

Abstract

PURPOSE:To decrease the fluctuations in output arising from a change in the environmental temp. of the short wavelength laser beam source by providing a Peltier thermoelectric element for executing the temp. control of a lens barrel. CONSTITUTION:A semiconductor laser 1 which generates a laser beam 2 of 0.84mum wavelength, a collimating lens 3, a half wave plate 4, a focusing lens 5, an optical wavelength conversion element 6 formed with an optical waveguide 7 on, for example, an LiNbO3 as a nonlinear optical crystal, a shaping lens 8 and the lens barrel 10 are provided. Further, a spacer 11 formed by using a heat insulating material is provided between the lens barrel 10 and a case 12 in the bottom of the lens barrel 10 and the Peltier thermoelectric element 13 is provided in contact with the base of the case 12. The temps. of the optical wavelength conversion element 6, the laser beam source 1 and the the lens 5 are kept constant and the optical at is misalignment and the fluctuation in the output of the laser beam source 1 by the change of the environmental temp. are decreased. The output of the short wavelength laser beam source is stabi lized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a short wavelength laser light source used for optical measurement, etc., and a method for manufacturing the same.

Conventional technology As a conventional short wavelength laser light source (for example, [G, T
ohmon, K., Yamamoto and
T, Tan1uchi)'o sheepゝ4nkゝ,
Niss Be I I (Proc, 5PIE) Vol.
, 898 Miniature 0ptics an
d La5ers (1988)].

Figure 3 (Dai) shows the configuration of a conventional short wavelength laser light source, 10 is a mirror, 6 is an optical wavelength conversion element in which an optical waveguide 7 is formed on a substrate of a nonlinear optical crystal such as LiNbo 3, and l is a laser beam 2 with a wavelength of 0.84 μm attached to the lens barrel 9 at the end opposite to the optical wavelength conversion element 6.
3 is a collimating lens X located on the laser beam output side of the semiconductor laser 1; 5 is a focus lens located on the light incident surface side of the optical wavelength conversion element 6;
4 is a half-wave plate located between the collimating lens 3 and the focus lens 5; 8 is a shaping lens for collimating the laser beam emitted from the light output surface of the optical wavelength conversion element 6; 9 is a main short-wave plate; The operation of the conventional short wavelength laser light source configured as described above will be explained using the output laser light of the wavelength laser light source. Wavelength 0.8 emitted from semiconductor laser 1
The 4 μm laser beam 2 enters the collimating lens 3 and becomes a parallel beam, and the deflection direction is corrected by the half-wave plate 4.
2U of laser light that enters the focus lens 5 is focused on the light incident surface of the LiNbO3 optical wavelength conversion element 6, propagates through the optical waveguide 7, and has a wavelength of 1
/2. The laser beam with a wavelength of 0.42 μm emitted from the LiNb0a optical wavelength conversion element 6 is passed through the shaping lens 8.
The output angle is corrected by
Problems to be Solved by the Invention Even when Emitted from O It has been found that the output of the laser beam 9 fluctuates by more than 10% due to a change in the output of the laser beam 9. It has become clear that such a fluctuation in output caused by a change of only ±10°C is a major problem in actual use. , this improvement is strongly desired, and in view of this, an object of the present invention is to provide a short-wavelength laser light source with small output fluctuations due to changes in environmental temperature. An optical wavelength conversion element that uses a thermoelectric element and has an optical waveguide formed on a nonlinear optical crystal plate;
a laser light source, a lens that collects the laser light emitted from the laser light source and makes it enter the optical wavelength conversion element,
A short-wavelength laser is fixed on the same optical axis within a lens barrel, and a Peltier thermoelectric element is attached to the lens barrel or a case covering the lens barrel. The temperature of the optical wavelength conversion element housed in a cylinder, the laser light source, and the lens that collects the laser light emitted from the laser light source and makes it enter the optical wavelength conversion element is kept constant.Environmental temperature change The optical axis shift caused by the laser light source and the output fluctuation of the laser light source are reduced.
It has now become clear that the output of the short wavelength laser light source can be stabilized: the Peltier thermoelectric element is not brought into direct contact with the lens barrel, but instead is covered with the lens barrel and thermally isolated from the lens barrel. By attaching it to the case, it is possible to alleviate the influence of temperature ripples caused by fluctuations in the drive current of the Peltier thermoelectric element, and stable temperature control is possible. This figure shows the configuration of the short wavelength laser light source in , where 1 is a semiconductor laser that generates a laser beam 2 with a wavelength of 0.84 μm, 3 is a collimating lens 2, 4 is a half-wave plate, and 5 is a focus lens. 6 As a nonlinear optical crystal, for example, L iN bo
An optical wavelength conversion element in which a guiding waveguide 7 is formed on a substrate of s,
8 is a shaping lens X; 9 is an output laser beam emitted from the lens barrel 10; 12 is an aluminum case that covers the lens barrel 10; 11 is the bottom of the lens barrel 10 and is located between the lens barrel lO and the case 12; A spacer using a heat insulating material located in between, 13
14 is a Peltier thermoelectric element that is in contact with the bottom surface of the case 12; 14 is a heat dissipation fin that is attached to the surface of the Peltier thermoelectric element 13 that faces the case 12;
is, for example, foamed polyethylene as a heat insulating material located between the case 12 and the radiation fins 14 and filling the portion other than the Beltier thermoelectric element.

The temperature control action of the short wavelength laser light source in this embodiment configured as above will be explained. Peltier thermoelectric element 13
is a number in which one surface is in contact with the bottom of the case 12 and the other surface is in contact with the radiation fins 14 to perform heat exchange.
The temperature of the case 12 can be controlled and the temperature of the space inside the case 12 can be kept constant. Therefore, case 1
The temperature of the lens barrel 10, which is surrounded by the lens barrel 2 and fixed to the case 12 via the spacer 11, is kept constant, and the optical axis and the output of the semiconductor laser 1 are kept constant.
between O and case 12 (spacer 1 with heat insulating effect)
1 and the space 16, the thermal resistance is increased, and even if a temperature ripple occurs in the case 12 due to the operation of the Peltier thermoelectric element 13, the effect on the temperature of the lens barrel 10 is extremely small, making stable temperature control possible. As a result, the environmental temperature characteristics of this short wavelength laser light source (at 25 ± 10 °C, the temperature fluctuation of the lens barrel lO is less than ± 0.5 °C, the output fluctuation rate 1
The operation of the short wavelength laser light source of this embodiment shown in Fig. 1 (basically, it is different from the conventional short wavelength laser light source shown in Fig. 3), making it possible to achieve an extremely excellent performance improvement. Same (6) Identical components are given the same numbers and detailed explanations are omitted.

FIG. 2 shows the configuration of a short wavelength laser light source in another embodiment of the present invention, where 12 is the case 12 in the first embodiment shown in FIG. Peltier thermoelectric element, 17 is a heat radiation fin, 1
5 is a heat insulating material 44 In this embodiment, by using two Peltier thermoelectric elements, the temperature control range is widened, and the output fluctuation rate is less than 1% even with an environmental temperature change of 25±20°C, as described in the detailed explanation of the invention. According to the present invention, the output fluctuation due to environmental temperature changes of the short wavelength laser light source created in the lens barrel is reduced, and its practical effects are greatly improved, which greatly contributes to the practical application of short wavelength laser light sources. It's something to do.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a short wavelength laser light source according to an embodiment of the present invention. FIG. 2 is an external view of a short wavelength laser light source according to another embodiment of the present invention. FIG. It is a sectional view of the main part. 1...Semiconductor Lasermi 3...Collimating train X
4... Half-wave plate, 5... Focus lens 6.
...LINbOs optical wavelength conversion element, 7... optical waveguide
8... Orthopedic lens
- Heat dissipation fin. Name of agent: Patent attorney Akira Okaji and 2 others

Claims (2)

[Claims] (1) An optical wavelength conversion element in which an optical waveguide is formed on a substrate made of a nonlinear optical crystal, a laser light source, and a lens that collects the laser light emitted from the laser light source and makes it enter the optical wavelength conversion element. 1. A short wavelength laser light source comprising a Peltier thermoelectric element fixed on the same optical axis within a lens barrel and for controlling the temperature of the lens barrel. (2) An optical wavelength conversion element in which an optical waveguide is formed on a substrate made of a nonlinear optical crystal, a laser light source, and a lens that collects the laser light emitted from the laser light source and makes it enter the optical wavelength conversion element. A short method characterized in that a Peltier thermoelectric element fixed on the same optical axis within a lens barrel and for controlling the temperature of the lens barrel is attached to a case that is thermally isolated from the lens barrel. A method for manufacturing a wavelength laser light source.