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BrightLock®
Brightlock®
achieves
spectrum control from a monolithic high power diode laser with an
internal
grating, thereby eliminating the need for any external optical elements
and reducing cost and increasing overall device robustness without
compromising reliability of efficiency.
BrightLock®
laser diodes offer :
1.
Spectral Width: < 0.5 nm (5X
narrower)
2.
Δλ/ΔT : 0.07nm/°C (4X lower)
3.
Center wavelength : ± 1 nm (3X more accurate)
Available at 780nm, 795nm, 808nm, 880nm, 885mn, 894nm,
976nm, 981nm, 1532nm, 1908 nm.
1. First, the 0.2 nm
FWHM spectrum is significantlynarrower than the 1.5-4.5 nm FWHM
typically achieved in conventional high power diode lasers without a
grating. The narrower spectrum increases pumping efficiency for any
medium with narrow absorption peaks (such as Yb, Rb, Er:Yag or glass,
Ho:Yag), and the repeatability of the
spectrum allows laser designers more flexibility in their system
architectures.
2. Another major
difference between devices with an internal grating and conventional
diode lasers is the lower wavelength - temperature coefficient. For
conventional diode lasers (<1064nm), this coefficient is
0.3nm/degC while for
devices with internal gratings, it is 0.07 nm/degreeC. This reduction
in temperature sensitivity relaxes the requirement for thermal
stabilization, enabling systems with reduced size and weight.
3. A third major
difference is the significantly improved center wavelength accuracy
achieved in the manufacturing process. Conventional pump lasers are
typically provided with a +/- 3 nm center wavelength tolerance due to
growth control and uniformity factors, as well as effects related to
bonding stress. Slightly narrower spreads (~+/- 2 nm) are achievable at
higher cost by selecting from the wavelength distribution of the pumps.
On the other
hand, the wavelength of devices with internal gratings is determined by
the period of the grating which can be controlled accurately and is
unaffected by growth uniformity. This enables +-0.5 nm spread in
devices from growth to growth and wafer to wafer. The improved accuracy
of center wavelengths from the manufacturing process results in a
reduction in the systems thermal management requirements, increased
system compactness and reduced weight. Moreover, because the diode
lasers are also operated over a narrower temperature range, the
lifetime of the diodes is expected to be more uniform in a given laser
design.
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