Vescent Photonics
D2 Series Product Manual
1.
DBR Laser Module
Model No. D2-100
1.1.
Description
The DBR laser module is comprised of a distributed feedback (DBR) laser diode in a precision
temperature-controlled housing with beam conditioning optics and an optical isolator. DBR laser diodes
are fabricated with the feedback grating patterned directly over the gain section of the diode. They are
highly immune to vibrations and by virtue of a very short cavity (~ 1 mm), they can be current tuned over
more than 50 GHz. The result is a robust laser capable of very fast servo control for easy locking to
atomic transitions. The module contains no moving parts or piezo-electrics and is therefore inherently
robust and rugged.
DBR lasers have 2-3 times larger temperature and current tuning coefficients as compared to external-
cavity diode lasers. Vescent carefully controls these parameters with two stages of temperature control
and a precision low-noise current controller with fast servo input.
The DBR laser is collimated by a 0.55 NA lens mounted to a movable plate for pointing adjustments.
The module also comes with a 35 dB optical isolator and a pair of anamorphic prisms. (Note that prior to
fiber coupling we recommend a second stage of isolation.)
The temperature controllers use an 8-pin circular connector on the back of the DBR subassembly. The
injection current connection to the laser diode is through an SMA connector also on the back of the DBR
subassembly.
5
