Mitsubishi Electric has launched new laser diodes with an emission wavelength of 642nm, which offer worldwide beam data with high dependability. The new laser diodes are available under the designations ML520G51-01 (as single emitters) or ML5xx50 (as multi-emitter-bars). In un-pulsed continuous operation (CW, continuous wave) the output is 150mW for the single emitters and 3W for the bars. Higher outputs are possible with pulsed operation - up to 6W with the bars.
Housing, service life and availability
The single emitter laser diode is accommodated in a hermetically sealed floating-case TO housing with a diameter of 5.6mm, whereas a CAN design with 25mm x 25mm edge length serves as a housing element with the bars. Both laser diodes are additionally available in an open variation (without cap) so that micro-optics can also be placed close enough in front of the chip. The start of mass production is planned for Q3/2007 (single emitters) or Q2/2008 (bars), respectively. The first preproduction test models are already available.
Consumer applications: displays and more
Mitsubishi Electric has developed the red laser diodes especially for utilisation in laser displays. On account of the small emitting area of 40µm with these new high-performance laser diodes, and in combination with the high outputs of the laser diodes, Mitsubishi is venturing into new technical realms and thus opening up other applications. The laser diodes can be utilised for illumination of displays (LCD or DLP) as well as for scanning-type displays. Utilisation in consumer displays is also possible, since suitable passive cooling systems are sufficient for cooling in many cases. This laser diode is also particularly attractive for fibre coupling, since a high degree of coupling-in (coupling efficiencies) can be achieved for glass fibres with a fibre diameter of up to 50µ m. The polarisation of 80:1 (TM) and the potential-free housing enable multiple combinations of individual emitters.
Industrial applications and medical technology
With appropriate active cooling, the 642nm laser diodes are also suitable for industrial and medical applications (photodynamic therapy, dermatology) in the range of 635nm, since the wavelength can be adapted in a relatively broad range through the relatively high temperature dependency of the wavelength (approx. 0.2nm/K). Individual or combined 642nm bars with aspecified long-term output (CW) of 3W can also be used for pumping CrLiSAF and Alexandrite in order to create a new generation of tuneable solid-state lasers.
Laser diodes for displays
The well-known 660nm lasers from Mitsubishi Electric are already utilised in many RGB display laser systems (1.5 - 25W white light). For instance, ML101J27 dependably work together in multi-source array in systems with frequency-doubled green and blue beam sources in which blue laser diodes are also frequently utilised. Even today, new dependable RGB vector graphic systems based on solid-state lasers frequently replace the Ar+/Kr+ ion laser, which entails intensive maintenance and resource costs. Another great advantage here is the relinquishment of water-based cooling systems. Therefore, Mitsubishi Electric is one of the largest manufacturers for high-performance laser diodes in the 660nm range.
