A modulated Near InfraRed gain calibration system for a 'Violin-Mode' transimpedance amplifier, intended for advanced LIGO suspensions

Document #:

LIGO-G1401275-v1

Document type:

G - Presentations (eg Graphics)

Abstract:

This presentation shows how the AC to DC gain ratio was found for a single Photodiode (PD) detector and its transimpedance amplifier, intended for the detection of Violin-Mode (VM) resonances in the fused silica suspension fibres of Advanced LIGO. The PD was irradiated with a Near InfraRed beam of constant (DC) intensity, this having a (much smaller) AC modulation at a known frequency on top. The separate AC and DC output voltages from the VM amplifier then allowed the required ratio of AC to DC gain to be determined, giving a calibration point for that particular frequency of (VM) modulation.

Files in Document:

• A_modulated_NIR_calibration_syetem.pdf (1020.4 kB)

Topics:

• Suspensions

Authors:

• Nick Lockerbie
• Kirill Tokmakov

Keywords:

Violin-Mode shadow-sensor Transimpedance Amplifier Calibration