http://www.jinstartech.com/

General Attributes:

Thorlabs WM202 very good price

WM202

600 - 1700 nm Wavelength Meter

• Measure Wavelength, Coherence Length, and Power of a Laser From 600 nm to 1700 nm
• Wavelength Accuracy: 1 ppm (Internal Reference) or 0.3 ppm (External Reference, ±25 MHz Accuracy)
• Control via Device Interface, Thorlabs' Software, or SCPI Commands

Features

• Scanning Michelson Interferometer with Internal Stable Reference Laser
• Measures the Wavelength, Coherence Length, and Power of a CW Laser from 600 to 1700 nm
• Use with Internal Reference Laser or an External Reference Laser (Thorlabs' LLD1530 Frequency-Locked Laser Recommended)
• Slow Scanning Mode at 1 Hz or Fast Scanning Mode at 10 Hz to Trade Off Accuracy for Measurement Speed
• Device Control Options:
  • Directly With the Touchscreen Interface
  • Remotely With a PC and Thorlabs’ OPM Software (USB or Ethernet Connection)
  • Monitor Data Through a Web Viewer (Ethernet)
  • Remote Control With SCPI Commands (USB, Ethernet, or RS232 Connection)
•  Configurable Analog Output Error Signal for Feedback Loops

The WM202 Wavelength Meter is a compact, general-purpose wavelength meter designed for measuring the center wavelength of a CW laser from 600 to 1700 nm (bandwidth ≤10 GHz) with an absolute accuracy down to 0.3 parts per million. The power and coherence length of the laser are also measured simultaneously, allowing for the single longitudinal mode behavior of the input laser to be monitored. The input light is coupled into the device using an FC/APC fiber.