Figure 5 (above left).
The MAROON-X Front End
nearing completion at the
lab in Chicago.
Credit: Andreas Seifahrt
Figure 6 (above right). MAROON-X guide camera diagram showing the object fiber in the center (back-
illuminated), surrounded by three single-mode fibers. These three fibers allow us to triangulate the position
of the object fiber in real time during the observations. A tip-tilt mirror is used to center the stellar image on
the object fiber. For lab testing, an “artificial star” was created by placing a pinhole at the nominal telescope
focus and illuminating it with an f/16 beam. Two sky fibers, placed 20” from the object fiber in opposite
positions, are used to capture the sky background for a high-dispersion spectrum in MAROON-X and for a
time-resolved, low-dispersion spectrum with an external spectrograph. A calibration fiber transports light
from the spectrograph room to the telescope’s front end and is used to illuminate the object and one of the
sky fibers for flatfield and wavelength calibration frames. Credit: Andreas Seifahrt
the optical fiber that runs to the instrument
and will also include some optics and elec-
tronics, as shown in Figure 5. The Front End
components are integrated and undergoing
testing in Chicago at this time; the pre-ship
acceptance test is scheduled for late Octo-
ber. The plan is to commission the Front End
on the telescope first, using a simple detec-
tor, so that we are ready to commission the
MAROON-X spectrograph when it arrives
next year.
TOPTICA Laser Update
As a proven, stable laser platform, the new
TOPTICA fiber laser is expected to bring
more power and stability to Gemini North
(GN) laser operations. We continue to make
progress with the installation of the system
(Figures 7-10). With the old Lockheed Martin
Coherent Technologies laser removed and
telescope restored, we were able to begin
modifying the telescope to accept the new
laser and, in June, we began preparations to
install it.
60
GeminiFocus
The GN laser design allowed the creation
of a single housing for both the laser head
and Beam Injection Module Optical Bench.
We refer to the housing as GNEST (Gemini
North Enclosure System for TOPTICA). The
laser head within the GNEST is coupled to
the TOPTICA Electronics Cabinet (EC) by op-
tical fibers and communication cabling. We
maintained the fiber coupling during instal-
lation, which was quite demanding logisti-
cally and required careful planning.
The addition of new equipment high on
the telescope required additional counter-
balance weights for the telescope. These
weights were designed and added in se-
quence; doing so allowed us to install the
laser components (GNEST and EC) while
maintaining telescope balance through the
day (July 19th). We then installed the utili-
ties and services for the laser. Testing began
with power on August 16th, followed by
first open-beam verification on the 22nd.
Laser alignment through the optical path
to the Beam Transfer Optics Optical Bench
on the secondary was verified, allowing us
January 2019 / 2018 Year in Review