780nm laser frequency locking module

Short Description:

Cold atom experiments with Rb need lasers with specific frequency and Erbium group launches different frequency locking schedules for 780nm laser. We built up an all-fiber-connected frequency locking module with an integrated optical system and other optical fiber devices. This module can offer stable SAS or MTS signal and together with our laser controller Preci-Lock, frequency locking with good long-term stability is realized. The frequency difference between two lasers should keep to a constant value in some cold atom experiments. For 87Rb atom gravimeter, the frequency difference of cooling laser and repumping laser should be about 6.6GHz and for the two Raman lasers the value is 6.834GHz. PreciLasers has launched a specialized laser controller Preci-Beat for offset frequency locking in the range from 50MHz to 8GHz with beat frequency/phase locking technique.

Send email to us Download as PDF

Product Detail

Product Tags

Integrated optical module

With integrated spatial frequency-locking module, PreciLasers builds an all-fiber-connected frequency locking module. This module gives a stable SAS or MTS signal at Rb D2 line and the spectrum can offer error signal for frequency locking of 780nm laser.

Dimensions of integrated frequency-locking optical module

SAS and MTS signal from the integrated optical module

Multi-function laser controller

Erbium group offers a multi-function laser controller for frequency locking under different condition. The controller, which is named Preci-Lock，is integrated with modem, PID module and High-Voltage amplifier and it can work as error signal generator, PID servo and PZT driver at the same time. All function of Preci Lock is controlled by software with no physical button or knob. The controller can work in different mode under customized. Under internal-modulation mode laser is locked with SAS or AS while under external-modulation mode laser is locked with MTS or PDH technique.

For multi-channel lasers, Erbium group offers another laser controller Preci-Beat for offset frequency locking. Preci-Beat is integrated with PFD and PID module and is also controlled with software.

Front panel of Preci-Beat

SAS-locking

Frequency locking with SAS is based on Lock-in amplifier. Take the SAS of 85Rb atom as example, Preci-Lock get SAS signal from integrated optical module and generate error signal with lock in amplifier, the PID module in Preci-Lock will then lock the frequency of 780nm laser.

SAS and error signal in Preci-Lock software

We build two independent SAS-locking system for 780nm laser and take a laser beating test with their 1560nm seed laser. This can show the stability of frequency locking.