Simple and versatile heterodyne whole-field interferometer for phase optics characterization.

Area of Science:

• Optics and Photonics
• Interferometry
• Laser Technology

Background:

• Characterizing optical elements like lenses is crucial in various scientific and industrial applications.
• Thermal lensing effects can significantly distort wavefronts, impacting optical system performance.
• Existing characterization methods may lack the sensitivity or versatility for complex optical phenomena.

Purpose of the Study:

• To develop and investigate a wavefront sensor for characterizing thermally induced lenses and passive lenses.
• To demonstrate the sensor's capability in measuring thermal lensing and wavefront distortion.
• To showcase the versatility of low-coherence digital speckle interferometry for optical metrology.

Main Methods:

• Development of a wavefront sensor based on low-coherence digital speckle interferometry.
• Illumination of the optical setup using two slightly detuned red diode lasers to generate synthetic wavelength fringes.
• Utilization of transmitted light through a ground glass plate for fringe pattern visualization.
• Experimental validation using an Er-doped glass sample pumped by a diode laser and an ophthalmic progressive lens.

Main Results:

• Successful generation of whole-field contour interference fringes using the synthetic wavelength technique.
• Accurate measurement of the thermal lens induced in an Er-doped glass sample.
• Precise evaluation of wavefront distortion introduced by an ophthalmic progressive lens.
• Demonstration of the sensor's performance and versatility.

Conclusions:

• The developed wavefront sensor is effective for characterizing both thermally induced and passive lenses.
• Low-coherence digital speckle interferometry provides a versatile platform for optical metrology.
• The sensor shows promise for applications requiring precise wavefront analysis, including ophthalmic lens evaluation.