Nichia announced "the world's highest level of" blue violet lasers and blue laser technology

Nichia in November 07 issued a pulse output power of blue violet 420mW semiconductor laser, and the continuous oscillation output power of blue semiconductor lasers 1W. The company said the output power of the two products are the highest level in the world". The output power of blue violet laser diode 420mW, high speed reading can be applied to Blu ray and HD DVD, a new generation of disc 2 layer 4 layer 6 or 12 speed speed writing. Currently on the market circulation of products, the maximum output power of 200mW, but the output power of 420mW is close to 2 times. The blue laser with output power of 1W is mainly used for projector with laser light source, and the output power is increased to two times. Nichia announced the high power laser technology and the background.

The output power of 420mW product production time of 09 years

The product of a blue violet semiconductor laser output power is 420mW, Nichia said the technology development has been completed. Life can be guaranteed in more than 5000 hours, electrical properties, such as product performance has reached a practical level. The company plans to start production in January 08 tons of 250mW products, after 1 years of mass production of 320mW products, the volume of production in the first 09 years of the release of 420mW products. Although the production volume is still too early, but the company hopes to quickly announce the completion of the development of the 420mW product news to promote the development of laser head manufacturers and equipment manufacturers in the development of high-speed reading and writing technology. However, in order to produce 420mW products, we must improve manufacturing technology to reduce manufacturing costs, and further improve the yield.

According to the introduction of Nichia chemical industries, before the output power of 250mW products unveiled, the development of a new generation of optical disk device has been influenced by the "blue purple power semiconductor laser 'restricted'" (LD Development Department Nichia LD Second Department of the Ministry of Technology Agency changbang Shen 1). Although the manufacturers want to improve the speed of reading and writing, but because of the semiconductor laser output power constraints, can not speed up the development of high-speed reading and writing equipment.

By increasing the output power of the blue violet semiconductor laser to 420mW, there will be no "power limitation" problem in the future. Although the 2 layer 4 layer 12 speed or 6 speed high speed read and write standard has not been specific decisions. However, the company stressed that as long as the output power of 420mW, blue violet semiconductor lasers can fully support the high-speed.

The release of the 420mW product threshold current of 30mA, the current can be obtained through the 300mA output power of 420mW. In actual production, the use of the equipment will be required to adjust the laser characteristics, such as a slight increase in luminous efficiency, etc.. However, even if these changes are added, it will not deviate too much from the published performance indicators.

The key to improve the output power is the reduction of COD and the resonator up to 1mm

420mW products in order to improve the output power, the implementation of the two improvements. The first is to reduce the catastrophic optical damage (COD:catastrophic optical damage) of the end face of the laser chip. The end face of the chip is the part of the laser, the higher the output power of the laser, the higher the surface is. Nichia did not disclose the specific circumstances of the technology, but without increasing cost range, can reduce the import of COD technology "(the board of directors of the company, the second sector LD of the Department of the minister and director of the Institute of nitride semiconductor Mukai Takashi).

Another improvement is the extension of the resonator of the oscillating laser. The specific value is not open, but the high power products of the red semiconductor laser, the resonator length is extended to about 2mm. A blue violet semiconductor laser resonator is not so long, only half of the red semiconductor laser around "(Nichia Mukai Takashi), so the estimate is about 1mm.

Extension of the resonator is to increase the size of the chip. Due to the reduction in the number of chips that can be obtained from 1 wafers and the effect of the crystal defects, it is possible to reduce the yield. In other words, the chip manufacturing costs will increase. In order to solve this problem, Nichia reduces the chip width (should, opposite direction perpendicular to the extending direction of the resonator chip size), to avoid increasing the chip area. In addition, the company plans to improve manufacturing technology to improve the yield.

Output power of 1W products will be 08 years from September to mass production

For the purpose of the display output power of 1W blue semiconductor laser, the sample delivery time is 08 years in March, and is scheduled to start production in September. Projector light source for color reproduction using red, blue and green lasers.

To improve the output power, the temperature rise of the laser chip and the serious deterioration of the laser chip will occur. The 2 times, Nichia power output will be increased to the original problem, the temperature rise, solved by encapsulation; deterioration of on chip, solved by improved chip. With these improvements, the lifetime of the output power can be up to more than 30 thousand hours when used for display purposes.

Packaged by the original product using a diameter of 5.6mm CAN package, changed to a diameter of 9mm the same package. As a result, the thermal resistance of the package can be reduced from the original 15K/W to 9K/W. By reducing the thermal resistance, the chip heat can be easily released to the outside of the package, as far as possible to reduce the temperature rise of the chip. Nichia said that the diameter of CAN 9mm package