June 4, 1998
Hitachi Releases Two High-output Red Semiconductor Laser Diodes for Laser Leveler- Features are continuous optical output of 15 mW in the 635-nm band and wide operating temperature range -Improved visibility, higher outputs, and wide operating temperature ranges have become important technological issues for red semiconductor laser diodes. This is especially true for products in which apparent brightness is an important sales point, such as laser levelers and laser markers, which are used outdoors, and for optical applications in general. Thus there is now strong demand for laser diode products with a high output in the 635-nm band. Hitachi currently mass produces 635-nm band short wavelength semiconductor laser diodes with outputs of 5 and 10 mW for use in laser levelers and similar equipment. However, current applications that need high outputs are currently forced to use a 670-nm or 780-nm semiconductor laser diode, since these diodes are available in versions with outputs of 15 mW or higher, and to use a special-purpose receiver to verify the position of the laser beam. To respond to these market conditions, Hitachi has developed and is now releasing these two red semiconductor laser diodes, the HL6321G and the HL6322G, which provide a high output of 15 mW in the 635-nm band and also have a wide operating temperature range of -10 to 50 dgrees Celcius. These products adopt an AlGaInP multi-quantum well structure active layer*1 that uses an off angle and take full advantage of the MOCVD*2 technology in the crystal growth used to fabricate those layers. This allowed Hitachi to optimize the control of the number of active layers, the thicknesses of those layers, the carrier density, and other structural parameters, which enabled the achievement of stable single mode*3 oscillation in the 635-nm band. Furthermore, to achieve the high output of 15 mW, the reflective layers at the ends of the laser diode chip were optimized, and, at the same time a structure was adopted that prevents damage to the end surface of the laser diode chip. Introducing these new technologies, made it possible to achieve the highest output level (Po = 15 mW, continuous operation) in this device class and the high continuous operating temperature of Tc = 50 degrees Celcius. Thus these devices can be applied in areas that require high output levels and a wide operating temperature range. The addition of these devices to the Hitachi laser diode product line means that the company now offers 5, 10, and 15-mW products, giving its users a wider choice to match the needs of their applications. These products are provided in a fully hermetically sealed package that includes a built-in monitor photodiode (Hitachi package code: G type, 9-mm diameter). The HL6321G is a positive power supply drive lead connection product and the HL6322G is a negative power supply drive lead connection product. This allows a product that matches an existing drive circuit to be selected. Future plans in this area include the development of even higher output products, including products in the 30-mW class.
Application Product Examples
Pricing in Japan
Features
1. Achievement of a high output power of 15 mW
in the 635-nm band
2. Wide operating temperature range
3. Internal circuits: support for positive
and negative drive Specifications
Maximum Ratings (Tc = 25 degrees Celcius)
Electrical and Optical Characteristics (Tc = 25 degree Celcius)
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