Some features of NV. Vincent Loriette

NV main objectives Evaluate the effect of imperfections on the shot-noise limited sensitivity. Fix some tolerances. Find free parameters optimal values (modulation depth, démodulation phase, etc.)

NV main features All optical parameters can be varied. Free mirror shapes. Free orientation and shape of the incident beam. Free modulation amplitude and frequency. … Fields are represented as finite sums of HG functions (no FFT). Fast code. No diffraction in free space. Not suited to work with exotic beam shapes. Optimization steps use realistic error signals. Realistic resonnance and antiresonnance seeks. Not necessarilly optimal (in the math sense).

Computation example : north arm refectance ORFP_n=ORni_o+OTni_i*inv(OId-exp(-i*phi_n)*OFPn)*(OPna*ORne_i*OPna*exp(-i*phi_n))*OTni_o; Edges diffraction Mode réfléchi Airy peak,… Mode incident Roughness indiced mode coupling

Effects of heating North arm reflectance without… and with thermal effects (stable)

Various optimizations can be performed NV main window Various optimizations can be performed Each optical parameter can be associated with an experimental measurement datafile

Result window : north arm example

Result windows : beam example

Output beam shape (before OMC)

Sensitivity & modulation

Typical results Scalar defects Maps Maps+thermal Opt mod index 0.068 0.172±0.001 0.215 ±0.001 Opt demod phase 2 ±0 17 ±1 Finesse N 49.26 49.1 ±0.2 49.3 ±0.2 Finesse W 49.79 49.6 ±0.2 49.7 ±0.2 dF/F [%] 0.27 0.23 ±0.12 0.24 ±0.12 Asymmetry [%] 1.05 1.00 ±0.3 2.78 ±0.5 Stored power N [kW] 15.38 10.82 ±0 11.15 ±0 Lost power N [W] 0.23 4.11 ±1 3.70 ±1 Surtension N 31.37 31.18 ±0.02 31.15 ±0.02 Stored power W [kW] 15.55 10.91 ±0 11.27 ±0.3 Lost power W [W] 0.19 6.05 ±0.02 5.85 ±0.04 Surtension W 31.70 31.42 ±0.01 31.48 ±0.1 Carrier power on BS [W] 978.5 684.5 ±0.5 725.1 ±2 Sideband power on BS [W] 1.70 8.56 ±0.1 10.9 ±0.2 Reflected carrier [W] 17.84 8.42 ±0.01 9.82 ±0.08 Reflected sb [W] 0.027 0.24 ±0 0.26 ±0.01 CITF surtension Carrier 49.04 34.74 ±0.03 37.10 ±0.08 CITF surtension SB 36.49 29.01 ±0.02 24.0 ±0.1 Transmitted (detected) carrier [mW] 0.064 (0.064) 359 ±6 (1.6 ±0) 324 ±40 (3.5 ±0.1) Transmitted (detected) sb [mW] 18.7 (17.9) 93.0 ±0.8 (70.0 ±1) 125 ±2 (100 ±2) Sensitivity [*1E-23] 2.48 2.87 ±0.01 2.96 ±0.02