DPSS vs ECD Lasers: Are You Getting the Usable Power You Think You Are?

Diode-pumped solid-state (DPSS) and external-cavity diode (ECD) lasers are both ideal candidates for narrow-linewidth applications in the emerging quantum technology market. We will be describing some of the spectral performance differences between DPSS and ECD lasers in a poster presentation at Photonics West 2020.

Due to an increased spontaneous emission factor, the line-shape of ECDLs can broaden by approximately fifty times more than in DPSSLs. This suggests that some of the power is emitted outside of the specified linewidth of these systems. In other words, the application-specific useful power is less in ECDLs than in DPSSLs. This is attributed to power detector spectral bandwidths that are usually a few hundred nanometres wide - most of the noise terms are recorded in the output power specification.

Graph of normalised spectral power density vs frequency offset

We analysed recently published spectra and demonstrated that, for a standard Nd:YAG DPSS laser, the ratio of the application-specific useful power to the total power (or spectral density contract, s.d.c.) can reach 80%. For ECDLs, this figure can be as low as 25%. This suggests that compared to an ECD laser, a DPSS laser can provide three-times the useful power. The ability of DPSSLs is critical for quantum applications, where a narrow linewidth and high spectral power density are required.

Our analysis will be presented at SPIE Photonics West at 6-8PM, Tuesday 4 February at the Moscone Center, Level 3 West. You’ll also find UniKLasers at Booth 5053, UK Pavilion throughout the exhibition. Further in-depth investigations will be published in our white paper thereafter. If you wish to be notified of this publication, please follow UniKLasers on LinkedIn or Twitter. Alternatively, drop us a message in our live chat if you wish to subscribe to our quarterly email newsletter on quantum technology - our privacy policy applies.

Thank you for your interest and we hope to see you in San Francisco next month!


SPIE Photonics West Conference details: LASE Solid State Lasers XXIX: Technology and Devices - Novel Laser Concepts Session 4 - Poster Sessions (view at spie.org)