High-Power and Small-Package Green Laser

Figure 1 shows the basic structure of Ricoh's high-power diode pumped solid-state laser with small package volume. The structure utilizes key components and technologies for high power and compactness. (1) For compact pumping volume, a microchip laser and edge pumping are applied. (2) For the heating problem, composite laser crystal is applied. (3) For high-efficiency second harmonics generation, a bulk-type quasi-phase matching device is applied..

Figure 1: Basic structure of the high-power and small-package laser

Figure 2 shows our objective, the Tri Color Laser. This structure integrates the laser shown in Figure 1 for red, blue, and green.

Figure 2: Our objective, the Tri Color Laser

Figure 3 is a photograph of the green output of over 10W in CW operation. It is an experimental set-up utilizing microchip laser material and high-power pumping. Figure 4 is a photograph of the 150cm3 green laser unit with green power of 9.6W in CW operation.

Figure 3: Photograph of the green laser output	Figure 4: The 150cm 3 green laser unit

A 1mm-thick bulk-type quasi-phase matching device with MgO:LiNbO ₃ was developed using Ricoh's original method. Figure 5 shows a photograph of the quasi-phase matching device.

Figure 5: A bulk-type periodically poled MgO:LiNbO ₃ device with 1-mm thickness

An over 10W class high-power green laser with small package volume and low heating volume was realized. And for this laser, a 1mm-thick bulk-type quasi-phase matching device with MgO:LiNbO ₃ was developed using Ricoh's original method.

Considering the high efficiency and compactness of the new laser system, we think our microchip laser system has a great future as a visible laser source for various industrial applications.

• *This work was supported by the New Energy and Industrial Technology Development Organization (NEDO).
• *This work was conducted through collaboration with NINS and Oxide Corporation.