Erbium Microchip Laser Development 1 Erbium Yb Glass

Erbium Microchip Laser Development 1. Erbium: Yb: Glass and Er: Yb: Li. Nb. O 3 Status. 2. Problems with 980 nm Laser Pump. 3. Development Plans.

Erbium, Yb: Glass • No lasing using external cavity test setup. • Doping levels appear reasonable for a short (e. g. , 0. 5 mm or less) chip length. • Pump beam diameter too large/power too low. • Cavity mode diameter too large due to long distance between external mirrors.

Er, Yb: Li. Nb. O 3 • No new information – still trying to determine doping levels and reasons for excessive up-conversion losses. • Currently concentrating on Er, Yb: Glass development.

Current Plans 1 Have VLOC provide the following: 1. 0. 5 mm thick Er, Yb: Glass micrchips with integral HR (rear) mirror, and AR coated front surface for use with external small radius (e. g. , 5 to 10 mm) OC mirror. 2. 0. 5 mm thick Er, Yb: Glass micrchips with integral HR (rear) mirror, and OC (front) mirror. 3. 2. 9 mm thick Mg doped Li. Nb. O 3 with and without OC mirror on one end for use with (1), above. 4. Several smaller thicknesses and possibly several doping levels of (1).

Current Plans 2 • Microchips with both HR and OC mirrors should lase up against pump diode or fiber, or with at most simple focusing optics. This will confirm correct doping levels and provide a way of testing performance • Microchips with only HR mirror will be tested in a short cavity small radius (e. g. , 5 to 10 mm) mirror and when mated with the Li. Nb. O 3 section result in an composite crystal suitable for mode locking.

Configurations for Basic Lasing Tests

Configuration for Mode-Locked Laser

980 nm Pumps • We have ordered a high quality laser diode driver system to replace the one we have that tends to blow out expensive pumps! • We have ordered several 1 W fiber coupled pump diodes. The 125 um fiber core diameter is small enough that simple focusing optics should be adequate for the thin Er, Yb: Glass microchips. • We will be mounting several bare 1 W 980 nm pump diode chips.

Summary • Obtain new Er, Yb: Glass micrchips. • Putting together new pumps. • Quite confident that these will result in lasing.

Existing and New 980 nm Pumps