The Ondax NoiseBlock™ ASE Filters suppress the broad spectrum of spontaneous emission from laser diodes which provides a pure, ASE-free, single frequency laser.

The ASE Filter is a reflective volume holographic grating (VHG) with bandwidth of the order of 400 picometers and throughput greater than 90%. The VHG is purposely manufactured with a slant that provides an angular separation between the specular Fresnel reflection from the surface of the VHG and the filtered laser beam (top figure left).

A single frequency wavelength stabilized laser at 785nm is shown in the bottom left figure. The two curves show the laser ASE background with and without the ASE Filter. With the NoiseBlock™ ASE Filter, more than 90% of the single frequency line is conserved while removing at least 40dB of the broad ASE spectral background.

The combination of the SureLock™ wavelength stabilized laser and NoiseBlock™ ASE Filters provides a pure single frequency laser with greater than 80dB suppression ratio. The ASE background level in the bottom left figure is limited by the measurement capability of the Optical Spectrum Analyzer.

Power Handling: the glass material is resistant to average powers in excess of several kW/cm2 at 1064nm and peak power in excess of 170MW/cm2 peak power (fluence of 3.8 J/cm2) at 1064nm.

The NoiseBlock™ ASE Filter is available at custom wavelengths between 400nm and 2,500nm.

Print the Ondax Raman Brochure for future reference.

Call 626.357.9600 or e-mail requests to sales@ondax.com.