The TEC-420 series are amplified external cavity laser diodes based upon a Littman-Metcalf cavity.
This series has a master oscillator power amplifier cavity design that provides greater output power at the centre wavelength and across the tuning range. These lasers provide wavelength tunability with central wavelengths in the red, or infrared regions of the spectrum.
Output powers of up to 2500mW are available.
The tuning range is diode dependent. Two tuning ranges are provided. Adjustment screws built into the cavity manually tune the wavelength. Finer adjustment of the cavity for fine wavelength tuning is achieved through the built in Piezo actuator.
The coarse tuning range is typically 1-5% of the centre wavelength (5-40nm depending on the diode) and the fine wavelength tuning is typically of the order of 200GHz. The mode hop free tuning range of the TEC-420 series is up to 60GHz.
Peak output powers range from 500-2500mW. These depend on the initial centre wavelength of the laser diode wavelength and the wavelength that it is tuned to. Output power varies with wavelength and tends to decrease as the laser is tuned away from the central wavelength. This variation approximates to a broadened Gaussian function. Historical tuning curves showing the output power achieved across a wavelength spectrum are available upon request.
The TEC series of external cavity laser diodes are provided in two different cavity configurations; Littrow and Littman. Littrow cavity designs tend to generate higher power whereas Littman cavity lasers have wide wavelength tuning and narrower linewidth.
All of the lasers in the TEC-420 series are based upon an amplified Littman-Metcalf cavity. The laser linewidth is approximately 1MHz over 10msec.
Each laser diode used in the range is antireflection coated using a proprietary process to achieve a facet reflectivity of less 1x10e-4. The low reflectivity ensures that maximum cavity coupling takes place. This results in superior line narrowed performance and cavity stability. This in turn provides lower optical noise, output power stability and alignment tolerance.
Each system comes with a benchtop controller (code:Pilot). The controller is compatible with single phase 240VAC (13A) mains electricity. It includes a key switch, emergency stop and interlock interface. The unit is fully featured, providing a range of different adjustment parameters of the laser via the menu driven software. An RS232/USB interface allows remote control of the system via PC. The controller also provides fine adjustment of the cavity via the Piezo actuator.
The output beam profile of these lasers is elliptical and astigmatic. The laser head is provided with a fixed collimation lens. Beam circularisation optics or fibre coupling (multimode or singlemode fibre) are also available as options. An optical isolator can be incorporated as an additional option.