SAM LGS-v1, Optics, The Laser Box position on SOAR IR Nasmyth Optical Nasmyth At 67.5Deg from IR Nasmyth Note: Laser umbilical cord of 7m has been tested. It can be laid out along the elevation ring passing directly to the cable ladder on the Nasmyth bearing and under the IR Nasmyth platform (tb/re-checked by SOAR team).
SAM LGS-v1, Optics, The LGS system M6 S-B-C B-E LaserLaser Laser Box: Laser: JDSU Q301-HD B-E: Special Optics x-351 CA-in=10mm,out=30mm, $2450. S-B-C: Special Optics UV-25 CA=25mm, $4150. Launch Telescope M1: R=1000mm, C= , =300mm. M2: R=30mm, C=0, =9mm. M3 M1 (pupil) M2 M6 M5 M4 M3 Beam Propagation: Laser-line (broad band?) Mirrors Diameter=30mm, R~99%. 22.5deg
SAM LGS-v1, Optics, The Laser beam and Spot Characteristics Laser Beam Quality: M²<1.2 TEM00 purity better than 90% Waist (TEM00)=0.13mm B-E magnification = 4x, places parallel beam waist =4mm on LLTM2. LLT magnification = 33.32x places waist image = 39.4mm at 10km. Mixed Mode results for M2 = : Sur Size Waist Position Radius Divergence Rayleigh LLTm E E E E E E+004 LGS IMA E E E E E E+006 Note: B-E of 8x degrades LGS IQ (though still diffraction limited) but has the advantage of lower energy density on beam propagation mirrors.
SAM LGS-v1, Optics, Polarization Strategy Laser Linear /4 Nasmyth Circular /4 Linear WFS module Expected Residual Ellipticity: de-phase in SAM common path (tb/measured). p= /2
SAM LGS-v1, Optics, LGS delivery System Tolerances LGS delivery system Tolerances Surface ShapeDisplacement Tilt ComponentConicRadius Max. rMax. (mm) (Deg) B-E m m m m LLTm LLTm11.08E LLT Max. Z (tolerance on m1-m2 distance) = 7.25um
SAM LGS-v1, Optics, mm 1.3min SOAR flexure: LLT Tilt and Decenter (the effect on image shift and quality) 2.3Arcsec
SAM LGS-v1, Optics, Displacement and Tilt correction Input beam angle= Deg; corrects +2.3mm of LLT displacement. LLT M1 tilt angle=-0.894Arcsec; corrects 2.3Arcsec of image shift ”=2.167um actuator push-pull Conclusion: M6 and M4 motorized tip-tilt for easier alignment. Beam Active control: 4 diodes at the edge of LLTM1 close loop on M4.
SAM LGS-v1, Optics, To Do List Define the beam transfer Mirrors now!. The Alignment Plan and alignment tools. Finish the Laser Box design (beam quality control and alignment gadgets). The Optical Component List for PO. The Documentation for PDR.