The Matisse is available with three levels of frequency stabilization: Passive stabilization with phase lock loop, active stabilization with reference cell, and active stabilization with Pound-Drever-Hall locking for ultranarrow linewidths to <30 KHz (100 ms integration time).

Superior mechanical stability, specially designed optical mounts, unique tuning methods, and the preferred Out of Plane cavity design of the Matisse C all contribute to the exceptional mode-hop-free scanning range of >50 GHz. In order to take this to the next level, we have developed “Scan Stitching” for wide mode-hop-free tuning over the full wavelength range (up to 300 nm).

CW single frequency ring lasers utilize a Phase Lock Loop (PLL) in order to stabilize the laser cavity to a single longitudinal mode. The Matisse incorporates a unique PLL technique that delivers low dither frequencies (down to 500 Hz) to minimize laser noise and allows easy adjustability of the frequency (500 Hz – 3 kHz) via software.

The Matisse can counteract the wavelength drift which is specific to any tunable CW single mode laser. To further counteract drift for a Matisse without reference cavity, a good wavemeter can be used as reference. Or for a Matisse laser with reference cavity an optional strain gauge can be installed on the scanning piezo. It is also possible to use the Matisse reference cavity as a transfer cavity or to stabilize it to an atomic resonance or a frequency comb.

The Matisse 2 R-Series ring laser with its mechanically quiet design provides excellent passive stability and ultra-low noise, single-frequency operation. Electronically controlled wavelength-selecting elements—a birefringent filter, a thick etalon, and a thin etalon—keep the laser centered on a single longitudinal mode. This enables long, mode-hop-free wavelength scans while maintaining constant, low-noise output power levels.

The Matisse 2 TR Ti:Sapphire ring laser provides a spectral linewidth of <4 MHz and can be readily upgraded to the higher resolution Matisse 2 TS. In fact, because of its modularity, any Matisse 2 laser can be field upgraded to either a Ti:Sapphire or dye gain medium, or to a configuration with higher resolution – from an R-Series to an S-Series or an X-Series.

The Matisse 2 S-Series actively-stabilized ring laser incorporates an external reference cavity with feedback to a cavity-length-stabilizing fast piezo-driven mirror. To guarantee a truly independent frequency feedback signal, the reference cavity is thoroughly isolated against thermal and mechanical perturbations and is fiber coupled outside the laser housing.

The Matisse 2 TS actively-stabilized Ti:Sapphire ring laser has an internal spectral linewidth of <50 kHz, while the Matisse 2 DS dye ring laser provides a spectral linewidth of <200 kHz.

The Matisse 2 X-Series ring laser provides spectral linewidths to <30 kHz for the Ti:Sapphire active gain medium, and <100 kHz for the dye laser. This ultra-narrow linewidth is the result of very fast cavity length stabilization with a response bandwidth in the MHz range. This is achieved by use of an intra-cavity electro-optic modulator (EOM).

Also key to achieving this ultra-narrow linewidth is the feedback error signal from the external reference cavity using the Pound-Drever-Hall stabilization scheme and a high finesse external reference cavity. Pound-Drever-Hall provides an unambiguous measure of wavelength position uninfluenced by laser intensity fluctuations.

The Matisse 2 TX-light fills the linewidth gap between the Matisse 2 TS and the Matisse 2 TX. It utilizes the Pound-Drever-Hall locking technique and the high-resolution reference cavity of the TX to provide the feedback signal to the fast Piezo-driven mirror of the TS. The negligible sensitivity of the Pound-Drever-Hall method to intensity fluctuations, as well as the extremely stable locking it provides, lead to laser linewidths of less than 50 kHz.