Overview

Finesse-40m is a twin to Finesse-LIGO. The functionality of Finesse-40m and Finesse-LIGO are very similar. The main factory object in Finesse-40m inherits from the Finesse-LIGO object. However, most of the methods are overwritten due to slightly different requirements and architecture.

Nonetheless, Finesse-40m has many Examples which can be trivially modified to suit of the Finesse-LIGO.

Finesse-40m was primarily developed in the summer of 2024 by Aaron Goodwin-Jones. It is based on a much earlier basic parameter file by Francisco Salces Carcoba and additional measurements by Aaron Goodwin-Jones, Francisco Salces Carcoba, Radhika Bhatt, Koji Arai, Kenny Moc, Jancarlo Sanchez and Rana Adhikari.

The authors thank Daniel Brown and Kevin Kuns for their advice and development of both Finesse and Finesse-LIGO.

This codebase replaces the earlier Finesse 2 models that had contributions from many people.

---

• Installation

• Examples
  • 40m Quantum Limited Sensitivity - PRMI
  • Time Domain Simulations
    • Overview
    • Validity of Time Domain models
    • Imports
    • Vanilla Simulation
    • Adding a controller
    • Changing Physical Attributes of Pendulum
  • Adding the AS beam on the AP Table (and QPDs)
    • Imports
    • Adding AS WFS
    • Checking the beam path
    • Locking the IFO
    • The sensitivity of WFS
  • Modifying the Input Path (Frequency Noise)
    • Modifying the Optical Path
    • Checking the build and locking the IFO
    • Measure the Response of the IFO to DARM
    • Measure the Frequency Noise Coupling
    • Project the Frequency Noise into DARM
  • 40m Custom Suspensions
    • Overview of Suspensions in Finesse LIGO-40m
    • Example - PRM to AS55_Q Transfer Function
    • Defining the factories
    • Building the Models
    • Running the Simulations
    • Plotting the Results
  • Noise in the PRMI Loop
    • Build the 40m Model with PRCL loop
    • Measure the Open Loop Transfer Functions
    • OLTF Comparison
    • Measure the Response of the IFO to DARM
    • Calibrate the Closed Loop Actuation Signal
    • Calibrate the Sensing Signal
    • Estimate the Quantum Noise in the PRCL Loop
    • Project the Sensing Noise into DARM

• Validation
  • Beam Tracing
  • 40m Quantum Limited Sensitivity - Simple Michelson
  • 40m Quantum Limited Sensitivity - PRFPMI

• Default Parameter file

• API Documentation
  • finesse_40m
  • finesse_40m package

• Appendix

• Glossary