A high power, two color, collinear, blue and green vertical external cavity surface emitting laser (VECSEL) is demonstrated. Two different InGaAs/GaAs VECSEL chips operating with gain centers near 970 nm and 1070 nm are used to make two separate V-folded laser cavities. Two critically phase-matched intracavity lithium triborate nonlinear crystals are used to generate blue and green outputs which are then combined in a polarizing beam splitter. This results in a single beam which contains over 10 watts of combined blue and green output power. This concept can be expanded upon by adding a red output for the creation of a high power, white laser source.
High power, tunable two color lasers are highly suitable for the new wavelengths generation thanks to various nonlinear
conversion phenomena. Vertical external cavity surface emitting lasers (VECSELs) are of special interest due to the
access to the high intracavity circulating power and wavelength control. We report a novel VECSEL cavity design,
which can deliver high power, tunable two color emission. The VECSEL setup is based on a two-chip T-shape cavity
configuration which utilizes a polarizing beam splitter to combine two VECSEL cavities. This allows for two-color
orthogonally polarized high-power collinear outputs. The two color emission of this kind is ideal for type II nonlinear
frequency conversion. A high-Q folded T-cavity is utilized to achieve the combined beams circulating power in excess of
175 W. Intracavity birefringent filters are used to facilitate tunability and wavelength separation between two colors. A
configuration of this type is used for high power intracavity type II sum frequency generation, which resulted in tunable
blue emission with above 750 mW output, and in the second case a tunable green emission with more than 1.4 W output
was obtained. A signal around 1 THz was achieved through type II difference frequency generation in tilted periodically
poled lithium niobate. Lastly, a silver thiogallate was utilized to generate mid-IR wavelength around 5.36 μm through
type II difference frequency generation.
Two-color, high-power, tunable lasers are highly beneficial for the generation of new wavelengths through various
nonlinear methods. Vertical external cavity surface emitting lasers (VECSEL) are particularly flexible for intracavity
wavelength control. We report a novel VECSEL cavity capable of generation high-power, tunable, two-color generation.
The laser employs overlapping VECSEL cavities in a two-chip T-shape cavity configuration which uses a polarizing
beam splitter/combiner to fold one cavity and thus allows for two-color orthogonally polarized high power outputs. The
tunable collinear, orthogonally polarized two-color is ideal for type II nonlinear conversion. A continuous wave (CW)
output power in excess of 13 W for the two-color emissions was demonstrated to be the sum of the output from each of
the overlapped cavities. In a high Q cavity, birefringent filters were used to facilitate tunability, and wavelength
separation was varied from 35 nm to 52 nm. In a modified T-Cavity configuration, high power intracavity type-II sum
frequency generation resulted in tunable blue-green emission with more than 750 mW output. By selecting identical or
different chips in the cavity, the wavelength separation and tuning can cover a wide range from zero to several hundreds
of nm opening doors for broad mid- to far-infrared applications.
Here we report on the development and demonstration of a tunable high power single frequency Vertical External Cavity
Surface Emitting Laser (VECSEL) operating at 589nm. A highly strained InGaAs/GaAs VECSEL designed to operate at
~ 1178nm is used in conjunction with an intracavity Birefringent Filter (BF) and low finesse Fabry-Perot (FP) etalon to
achieve the single frequency operation at the fundamental wavelength. An internal non-linear optical element is then
used to obtain the single frequency output at the desired wavelength of 589nm. Our results show outputs in excess of
4W at 589nm with a FWHM linewidth of the fundamental frequency to be less than 10MHz. We demonstrate the
measurement of the sodium D1 and D2 lines by passing the output through a reference cell.
In this paper we report on the wavelength tuning of a VECSEL by changing the cavity geometry. The development and
demonstration of a tunable high power single frequency Vertical External Cavity Surface Emitting Lasers (VECSEL)
operating at various wavelengths from the UV to the IR region of the spectrum have been reported in many papers.
However, it is important to understand that in many instances a precise lasing wavelength is required for proper
operation. For example, VECSELs have been designed to specifically interact with the sodium spectral lines. If the
VECSEL growth is not adequate, it may not be possible to reach the desired wavelength in a traditional cavity where the
intracavity mode interacts with the VECSEL chip at normal incidence. Here we notice that if a fold angle is introduced
at the VECSEL chip, a spectral blue shift occurs, and extended tunability may be possible. Therefore, by altering the
cavity geometry it may be possible to further optimize a VECSEL design to obtain maximum output power at a desired