How is the tuning achieved?
For the TLB-6300, we separate wavelength tuning of our lasers into coarse and fine tuning. Coarse tuning is accomplished by using a DC motor to turn a precision screw. An angle sensor incorporated in the laser cavity feeds back to the microprocessor to scan to the desired wavelength. On the end of the coarse tuning screw is a piezoelectric actuator (PZT). This actuator provides independent fine control of the laser wavelength and can also be used to modulate the laser frequency while it is being slowly scanned. For the fine tuning of the TLB-7000 and TLB-6000 lasers no DC motor is required, so we use the PZT to control the wavelength.
