Our Laser Line Longpass filters offer unprecedented performance in
longpass laser edge filter applications. The steep edges (measured
from an optical density of 6.0 to a transmission of 50%) make it
possible to measure even the smallest Raman shifts, making these
filters a superior alternative to costly holographic notch filters
for Stokes Raman scattering measurements. Compared to notch
filters, these edge filters offer better transmission, higher
laser-line blocking, and steeper edges, permitting measurement of
Raman signals extremely close to the laser line. The large
bandwidths and exceptional transmission permit these filters to be
used in even the most demanding imaging applications.
Several unique features enhance the overall value of our laser
Longpass filters. First benefit of our laser filters, the rejected
laser source light is reflected, easing stray-light management
issues associated with holographic notch filters. Eliminating the
need for complicated light baffling simplifies system design,
creating more compact, cost-effective instrumentation. Second
enhancing feature of our laser filters, with guaranteed transition
widths (measured from the laser wavelength to the 50% transmission
wavelength) of <1%, angle-tuning is unnecessary, greatly
simplifying system setup and implementation. And finally, the
patent-pending coating process ensures unrivaled laser filter
lifetime and durability, and guarantees "near-zero" temperature
dependence, ensuring low long-term cost of ownership and maximum
system operational range and sensitivity. These laser filters are
not intended for general purpose longpass applications, as they do
not have consistent blocking in the shortwave region.