Mitsubishi Electric’s new red laser diode for pico projectors

TOKYO, JAPAN: Mitsubishi Electric Corporation (TOKYO: 6503) announced the launch of a 638-nanometer (nm) wavelength red laser diode (LD), ML520G72, which offers the world’s highest output power in 638 nm band LDs, making it ideal for pico projectors and other portable display systems that require a red light source with high brightness. Sample shipments will begin on February 1.

Pico projectors have recently come to increasingly garner attention, being embedded in or connected to mobile systems such as cellular phones and laptop computers. Light emitting diodes (LEDs) and LDs are mainly used as the light source in these projectors because they can project a wider range of colors compared to lamp-based projectors.

Compared with LEDs, however, LDs deliver higher output power with less power consumption, enabling batteries to last longer. They also enable focus-free operation because optical systems with great depth of field can be used with laser beams.

In July 2009, Mitsubishi Electric launched a 638nm LD that offers 300 milliwatts (mW) output power, high brightness and pure red tone. The new LD offers an even higher output power of 500 mW, currently the world’s highest in 638 nm band, which helps achieve high-luminous projectors of up to 60 lumens (lm).

By comparison, LED-based projectors typically offer only about 10 lm. In addition, the new LD has an industry-leading electrical conversion ratio of 32 percent at 500 mW, and at a case temperature of 25 degrees C, which help to reduce power consumption in pico projectors.

The ML520G72 can also be operated at a temperature range of -5 to 40 degrees C when emitting 500 mW continuous waves (CW), and up to 50 degrees C under pulse operation at a duty ratio of 25% or less and frequency of 50Hz or higher.