General Parameters

*(Note: Output power may vary depending on the characteristics of the input pump laser, such as power and linewidth.)

Optical Layout for the Use of PPLN Frequency Doubling Crystal

Test example: 1560 → 780nm

First, select a 1560nm DFB semiconductor laser as the seed source and input it into an EDFA for optical amplification. The amplified fundamental wave light is then used as the pump source for the PPLN crystal. The light is input into the crystal's input port, and after passing through the PPLN, the frequency-doubled 780nm light is generated. Before injecting the pump, it is essential to ensure that the temperature controller of the PPLN is functioning properly and that the crystal is stable at the set temperature.

The 780nm output spectral component was tested using a spectrometer to confirm the frequency doubling process. The spectrum is shown below:

By adjusting the EDFA current, we tested the frequency doubling power variation with different input powers. Higher input power results in higher frequency doubling efficiency.

Finally, we tested the power and frequency stability of the output frequency-doubled light, verifying the operational stability of the PPLN crystal. These two parameters also depend on the noise of the EDFA and DFB, requiring a low-noise light source for testing.

Power stability test:

Precautions:

The waveguide must be properly heat managed. It is recommended to mount the waveguide on a heat sink, with thermal conductive materials like thermal grease applied to the contact surface between the waveguide and the heat sink. The    recommended operating environment temperature is 10~30°C. If the temperature is outside this range, secondary temperature control for the heat sink should be applied, setting the heat sink temperature around 20°C. It is strictly prohibited to operate without secondary temperature control in environments exceeding the waveguide's matching   temperature.

The matching temperature of the waveguide body must be in the range of 20~60°C.

Start the waveguide's temperature control first, wait for the temperature to stabilize, and then slowly increase the pump   power. As the pump power increases, the optimal matching temperature of the waveguide may shift slightly. At this point, fine-tune the waveguide temperature to achieve maximum frequency-doubling output.