Fiber optic, photonic & electronic test & measurement
SYCATUS / Keysight

A0040A Optical Noise Analyzer

An analyzer that measures the optical frequency noise of a laser as a power spectral density, and separates the 1/f noise from the white noise so a white-noise (Lorentzian) linewidth can be derived. It also includes a conventional delayed self-heterodyne linewidth mode.

A0040A Optical Noise Analyzer

Technical overview

A SYCATUS optical test set feeds a Keysight X-Series signal analyzer running Keysight VSA software; SYCATUS states the method needs no reference laser source and no frequency tuning, so measurement starts as soon as the laser is connected. Because the instrument resolves the noise spectrum rather than only a linewidth figure, SYCATUS states it can show spurious noise caused by dither or EMI, which matters for ITLA development. A fast scan mode is provided for real-time adjustment of laser conditions. The A0040A can share a signal analyzer with the A0010A RIN Measurement System, and the A0070A Optical Frequency Analyzer can be added as an option.

Features

  • Optical frequency noise captured as power spectrum density
  • 1/f noise, white noise and Lorentzian linewidth analysis
  • High sensitivity, sub-1 kHz linewidth measurement
  • Includes conventional delayed self-heterodyne interferometer function
  • Novel fast sweep mode for real-time tuning of laser conditions
  • Analysis of lasers for digital coherent transmission and sensing systems
  • Can share the same Keysight X-Series signal analyzer with the A0010A RIN Measurement System
  • A0070A Optical Frequency Analyzer available as an option

Specifications

Specifications
ParameterValue
Optical wavelength1520 to 1620 nm
Optical frequency noise measurement bandwidth, 12.5 MHz model5 Hz to 12.5 MHz Hz
Optical frequency noise measurement bandwidth, 20 MHz model5 Hz to 20 MHz Hz
Optical frequency noise measurement bandwidth, 80 MHz model5 Hz to 80 MHz Hz
Optical frequency noise sensitivity, typ. (at 10 MHz)10 Hz^2/Hz
Optical wavelength range options (datasheet)1520 - 1620 nm, 1260 - 1360 nm, or 1260 - 1620 nm nm
Optical frequency noise analysis bandwidth (datasheet; max. depends on the signal analyzer's specification)min. 5 Hz; max. 12.5 MHz, 20 MHz, 80 MHz, 127.5 MHz or 255 MHz Hz
Optical frequency noise floor, standard mode (at 1 MHz, datasheet)6 mHz-rms^2/Hz
Optical frequency noise floor, high-sensitivity mode (at 1 MHz, datasheet)0.6 mHz-rms^2/Hz
Input optical power range (datasheet)-7 to +3 dBm
Measurement time, standard mode, 50 averages (datasheet)< 20 s
Measurement time, high-speed scan mode, 50 averages (datasheet)< 0.5 s
Source: https://sycatus.com/en/products/a0040a/ · retrieved 2026-08-25
Specifications are reproduced from the manufacturer's own published material on the date shown and are subject to change. Confirm at order.

Applications

  • Spectral purity evaluation of laser sources for digital coherent transmission
  • ITLA development, including detection of spurious noise from dither or EMI
  • 1/f noise, white noise and Lorentzian linewidth analysis of narrow-linewidth lasers
  • Characterization of lasers for optical sensing systems
  • Conventional delayed self-heterodyne linewidth measurement and simulation
Manufacturer datasheet (PDF)

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