Full characterization wavefront sensor

• US 9,976,911 B1
• Filed: 06/29/2016
• Issued: 05/22/2018
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Beam Engineering For Advanced Measurements Co.
• Original Assignee: Beam Engineering For Advanced Measurements Co.
• Inventors: Tabirian, Nelson V., Liao, Zhi J.
• Primary Examiner(s): Decenzo, Shawn
• Application Number:
  US15/196,679
• Time in Patent Office: 692 Days
• Field of Search: None
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/4257 applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam monitoring arrangements for lasers in general H01S3/0014
• CPC Class Codes: G01J 2009/002 Wavefront phase distribution
• CPC Class Codes: G01J 9/00 Measuring optical phase difference devices or arrangements for controlling the phase of light beams G02F1/01; Determining degree of coherence; Measuring optical wavelength spectrometry G01J3/00

Abstract

Sensors, devices, apparatus, systems and methods for replacing microlens arrays with one or more switchable diffractive waveplate microlens arrays for providing measurements of wavefronts and intensity distribution in light beams with high spatial resolution with a single optical radiation sensor. The device acts like a conventional Shack-Hartmann wavefront sensor when the microlens array elements are in focusing state, and the device performs light beam intensity profile characterization acting as a beam profiler when the optical power of lens array elements is switched off.

Claims

1. A Shack-Hartmann wavefront sensor, comprising:

a sequence of switchable diffractive waveplate microlens arrays in series;

an optical sensor array having an output; and

an electronics system for reading, analyzing and displaying the output of the optical sensor array in order to derive the phase of optical wavefronts and intensity distribution in a beam incident on the Shack-Hartmann wavefront sensor.

2. The wavefront sensor of claim 1 in which the sequence of switchable microlens arrays comprises at least one switchable diffractive waveplate liquid crystal microlens arrays.

3. The wavefront sensor of claim 1 in which the electronics system for reading, analyzing and displaying the output of the optical sensor array allows measurements of a wavefront and intensity distribution of the incident beam for varying settings of the switchable diffractive waveplate microlens arrays.

4. The wavefront sensor of claim 1 in which at least two switchable diffractive waveplate microlens arrays in the sequence have the same microlens pitch.

5. The wavefront sensor of claim 1 in which at least part of the switchable diffractive waveplate microlens arrays in the sequence have a different pitch.

6. The wavefront sensor of claim 1, further comprising a circular polarizer at the input of the optical sensor array.

7. A Shack-Hartmann sensor system, comprising:

a sequence of at least two switchable diffractive waveplate microlens arrays in series for receiving an optical wavefront; and

an optical sensor array having a plurality of pixels, wherein the sequence of at least two switchable diffractive waveplate microlens arrays focuses the optical wavefront on a focal spot of the optical sensor array for the Shack-Hartmann sensor system.

8. The sensor system of claim 7, wherein the sequence of the at least two switchable diffractive waveplate microlens arrays includes:

a first switchable microlens array in parallel and spaced apart from a second switchable microlens array.

9. The sensor system of claim 7, wherein the optical detector array includes:

a focal plane array (FPA).

10. The sensor system of claim 7, wherein the optical sensor array includes:

a CCD (charge-coupled device) array.

11. The sensor system of claim 7, wherein the optical sensor array includes:

a CMOS (complementary metal-oxide semiconductor) array.

12. A Shack-Hartmann sensor system for wavefront and intensity profile measurement of light beams, comprising:

a sequence of diffractive waveplate microlens arrays in series, wherein optical power of the sequence of diffractive waveplate microlens arrays is cycled between focusing and non-focusing states allowing to combine wavefront measurement of a light beam in focusing state with beam intensity profile measurement in non-focusing state for the Shack-Hartmann sensor system.