Optical Parameters
Parameter iLCGT mLCGT units Laser source Wave length 1064 1064 nm Initial Laser Power 10-20 20 W Injecting Laser Power into IFO 10-20 20 W Modulation depth -- -- RF freq 1 TBD (PM) 11.25 (PM) MHz RF freq 2 NA 45 (AM) MHz Primary parameters of interferometer Arm cavity Finesse 1546 1546 Arm cavity power gain 960 960 PR gain No PR ~10 PRC power on BS 10-20 200 W Cavity Length Arm cavity length 3000 3000 m PR cavity length No PR 73.2826 m Asymmetry length 3.33103 3.33103 m BS-FM length 25 25 m SR cavity length No SR 73.2826 m SRC detuning phase No SR 90 (BRSE) / 86.0 (DRSE) degree Mirror optical properties EM Reflectivity 0.999945? 0.999945? FM Reflectivity 0.996000 0.996000 PRM Reflectivity No PR 0.77 SRM Reflectivity No SR 0.85 BS Reflectivity 0.5 0.5 HR Coating Loss of EM and FM 45e-6? 45e-6? BS Loss -- -- AR Transmittance -- -- AR Coating Loss -- -- MICH contrast Other losses in PRC Other losses in SRC Mirror geometries EM mass 10.8 10.8 kg FM mass 10.8 10.8 kg PRM mass No PR 10.8 kg SRM mass No SR 10.8 kg BS mass 29.9 29.9 kg EM ROC 7260 or 7320 7260 or 7320 m FM ROC 7260 or 7320 7260 or 7320 m FM AR ROC Inf Inf m PRM ROC No PR TBD m SRM ROC No SR TBD m BS ROC Inf Inf m EM diameter/thickness 25 / 10 25 / 10 cm FM diameter/thickness 25 / 10 25 / 10 cm PRM diameter/thickness No PR 25 / 10 cm SRM diameter/thickness No SR 25 / 10 cm BS diameter/thickness 38 / 12 38 / 12 cm Mode Cleaner MC1 length -- -- m MC2 length 26.648218 26.648218 m MC1 Finesse -- -- MC2 Finesse -- -- Output Mode Cleaner OMC length No OMC TBD m OMC Finesse No OMC TBD OMC input/output mirror reflectivity No OMC TBD OMC end mirror reflectivity No OMC TBD OMC MC FSR No OMC TBD MHz DC readout phase NA 113.4 (BRSE) / 125.8 (DRSE) degree Control Bandwidth Quantum efficiency 0.9 0.9 CARM control band width 30k? -- Hz DARM control band width 200? -- Hz PRC control band width No PR -- Hz MICH control band width 50? -- Hz SRC control band width No SR -- Hz Feed-Forward gain TBD --