This is a somewhat dated article from last year.
Indium gallium nitride (InGaN) laser diodes have reached a new frontier in performance: continuous-wave (CW) emission at green wavelengths longer than the 532 nm output of frequency-doubled Nd:YAG lasers. The previous long-wavelength record had been set by a 527 nm diode from Sumitomo Electric (Osaka, Japan). Now, a team from Sumitomo and the Advanced Materials Laboratory of Sony (Atsugi, Japan) reports diodes emitting more than 100 mW CW at wavelengths beyond 532 nm, and CW emission of unspecified power at 536.6 nm.
The success of these researchers could be a milestone in laser display and projector development. Doubled neodymium lasers can be used, but they require external modulation. Green laser diodes are more attractive, especially for mobile devices, because they can be directly modulated, are smaller, and can be more efficient. Laser-projector developers have been seeking 50 mW in the green with a wall-plug efficiency of 4.5%, according to Shimpei Takagi of the Sumitomo Semiconductor Technologies R&D Laboratories and colleagues.1
They also want diode wavelengths emitting in the 530–535 nm range, rather than the 515–520 nm of today’s commercial green laser diodes. For most applications, a 10 nm shift in wavelength would be of little importance, but laser projection is an exception because of the importance of green light in human vision.
One reason for this is that color-sensing cones in the eye have their peak response at 555 nm in the green, matching the peak in the solar spectrum at Earth’s surface. A second is that color perception depends on the relative response of the eye’s color receptors, and the green and red receptors are closely spaced, peaking at 540 and 570 nm, respectively. That response makes the green wavelength used in a laser projector particularly important in determining the gamut, or range of colors, that can be displayed. As shown in the International Commission on Illumination (CIE) diagram (see figure), the color gamut is largest for wavelengths of about 523 nm, but the optimum wavelength for displays is offset to 530–535 nm by the eye’s higher sensitivity to longer wavelengths.
More: SEMICONDUCTOR LASERS: Green laser diode emits at 536 nm - Laser Focus World
Indium gallium nitride (InGaN) laser diodes have reached a new frontier in performance: continuous-wave (CW) emission at green wavelengths longer than the 532 nm output of frequency-doubled Nd:YAG lasers. The previous long-wavelength record had been set by a 527 nm diode from Sumitomo Electric (Osaka, Japan). Now, a team from Sumitomo and the Advanced Materials Laboratory of Sony (Atsugi, Japan) reports diodes emitting more than 100 mW CW at wavelengths beyond 532 nm, and CW emission of unspecified power at 536.6 nm.
The success of these researchers could be a milestone in laser display and projector development. Doubled neodymium lasers can be used, but they require external modulation. Green laser diodes are more attractive, especially for mobile devices, because they can be directly modulated, are smaller, and can be more efficient. Laser-projector developers have been seeking 50 mW in the green with a wall-plug efficiency of 4.5%, according to Shimpei Takagi of the Sumitomo Semiconductor Technologies R&D Laboratories and colleagues.1
They also want diode wavelengths emitting in the 530–535 nm range, rather than the 515–520 nm of today’s commercial green laser diodes. For most applications, a 10 nm shift in wavelength would be of little importance, but laser projection is an exception because of the importance of green light in human vision.
One reason for this is that color-sensing cones in the eye have their peak response at 555 nm in the green, matching the peak in the solar spectrum at Earth’s surface. A second is that color perception depends on the relative response of the eye’s color receptors, and the green and red receptors are closely spaced, peaking at 540 and 570 nm, respectively. That response makes the green wavelength used in a laser projector particularly important in determining the gamut, or range of colors, that can be displayed. As shown in the International Commission on Illumination (CIE) diagram (see figure), the color gamut is largest for wavelengths of about 523 nm, but the optimum wavelength for displays is offset to 530–535 nm by the eye’s higher sensitivity to longer wavelengths.
More: SEMICONDUCTOR LASERS: Green laser diode emits at 536 nm - Laser Focus World
