Low phase noise master oscillator generation and distribution for ALS and ALS-U

TL;DR

This paper presents a modernized, low phase noise master oscillator distribution system for ALS and ALS-U, comparing optical transceivers and discussing phase noise optimization efforts and prototypes.

Contribution

It introduces a new low phase noise oscillator system and evaluates commercial optical modules for improved ALS-U operation.

Findings

Optical transceivers suitable for low phase noise distribution identified

Phase noise optimization techniques demonstrated

Prototypes of a frequency adjustable master oscillator shown

Abstract

The coax based MO distribution system in the ALS is going to be replaced by a modernized, lower phase noise and more interference tolerant version, ready to support ALS-U operation. System aspects are shown and several commercial analog and digital optical transceiver modules are compared for their suitability in this application. Furthermore, recent phase noise optimizing efforts in the ALS RF system are discussed and several prototypes for a custom built, low phase noise, frequency adjustable master oscillator around 500 MHz are shown.