Non-linear optical pumping detection apparatus and non-linear optical absorption cross-section measurement method

Patent metadata

Field	Value
Publication number	US-11719629-B2
Application number	US-202117781003-A
Country	US
Kind code	B2
Filing date	Jan 27, 2021
Priority date	Feb 28, 2020
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A non-linear optical pumping detection apparatus and a non-linear optical absorption cross-section measurement method, which can simultaneously measure degenerate and non-degenerate two-photon absorption cross-section spectra. The measurement process is automatic, efficient and fast. The working wavelength band is from 380 nm to near infrared 1064 nm, and the non-linear performance measurement of the super-continuous wide spectra can be realized. A zoom optical system with a larger entrance pupil diameter is adopted as a weak signal acquisition lens. So the weak signal can be effectively extracted from background noise. Meanwhile, the mean square root diameter of an on-axis image point of the zoom optical system is 100 to 150 microns, the divergence angle 2α of the on-axis image point is 30.6 degrees, which well match the optical fiber coupling condition, thereby improving the coupling efficiency of the space light coupling into the optical fiber, and greatly improving the measurement sensitivity.

First claim

What is claimed is:

1. A non-linear optical pumping detection apparatus, comprising a main light path, a non-degenerate detection system, a non-degenerate excitation system, a degenerate detection system, and a reference system, wherein
the main light path sequentially comprises a laser, a first aperture diaphragm, a chopper, a first polarizer, a second polarizer, a first reflector, and a first laser beam splitter;
the non-degenerate detection system sequentially comprises a second reflector, a first adjustable attenuator, a first converging lens, a heavy water tank, a second pinhole diaphragm, a neutral filter, a second converging lens, a second laser beam splitter, a third converging lens, a sample to be measured, and a first optical signal collection system; the first optical signal collection system is connected to an optical multichannel analyzer through a first optical fiber, and the optical multichannel analyzer is connected to a computer;
the non-degenerate excitation system sequentially comprises a second adjustable attenuator, a third reflector, a fourth reflector, a fifth reflector, a sixth reflector, a seventh reflector, an eighth reflector, a ninth reflector, a fourth converging lens, the sample, and an optical power meter; the laser passing through the third converging lens and the laser passing through the fourth converging lens are superposed at an angle 5 to 15 degrees in the sample;
the degenerate detection system sequentially comprises a third laser beam splitter, a triple prism, a fifth converging lens, the sample, and a second optical signal collection system; the second optical signal collection system is connected to the optical multichannel analyzer through a second optical fiber, and the optical multichannel analyzer is connected to the computer;
the reference system sequentially comprises a tenth reflector, the sample, and a third optical signal collection system; the third optical signal collection system is connected to the optical multichannel analyzer through a third optical fiber, and the optical multichannel analyzer is connected to the computer.

2. The non-linear optical pumping detection apparatus according to claim 1 , wherein
the third reflector, the fourth reflector, the seventh reflector, and the eighth reflector are arranged on a high-performance linear translation platform;
the first adjustable attenuator, the second adjustable attenuator, the first converging lens, the second converging lens, the third converging lens, the fourth converging lens, the fifth converging lens, the optical power meter, the first optical signal collection system, the second optical signal collection system, the third optical signal collection system, and the high-performance linear translation platform are separately connected with the computer through a control line;
a diameter of the first pinhole diaphragm is 5 mm, and a diameter of the second pinhole diaphragm is 10 mm; a frequency of the chopper is configured to be adjusted from 4 Hz to 10 KHz; a polarization direction of the second polarizer is horizontal; the first reflector, the second reflector, the third reflector, the fourth reflector, the fifth reflector, the sixth reflector, the seventh reflector, and the eighth reflector are all 45° to a main optical axis; the first beam splitter, the second beam splitter, and the third beam splitter are all 45° to the main optical axis; a transmissivity of the first laser beam splitter is 10%, and a reflectivity of the first laser beam splitter is 90%; a transmissivity of the second laser beam splitter is 50%, and a reflectivity of the second laser beam splitter is 50%; a transmissivity of the third laser beam splitter is 10%, and a reflectivity of the third laser beam splitter is 90%; focal lengths of the first converging lens, the second converging lens, the third converging lens, and the fifth converging lens are all 10 cm, and a focal length of the fourth converging lens is 50 cm; a thickness of the sample is 10 mm; the first optical signal collection system, the second optical signal collection system, and the third optical signal collection system adopt a same zoom optical system.

3. The non-linear optical pumping detection apparatus according to claim 2 , wherein
the same zoom optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens.

4. The non-linear optical pumping detection apparatus according to claim 3 , wherein
the first lens is an aperture stop;
the first lens, the third lens, the fourth lens, the sixth lens, the ninth lens, and the tenth lens, the twelfth lens, and the thirteenth lens are all positive lenses; the second lens, the fifth lens, the seventh lens, the eighth lens, and the eleventh lens are all negative lenses.

5. The non-linear optical pumping detection apparatus according to claim 3 , wherein
the first lens is a meniscus concave lens, the second lens is a meniscus concave lens, the third lens is a biconvex lens, the fourth lens is a biconvex lens, the fifth lens is a biconvex lens, the sixth lens is a biconvex lens, the seventh lens is a biconvex lens, the eighth lens is a meniscus concave lens, the ninth lens is a biconvex lens, the tenth lens is a meniscus concave lens, the eleventh lens is a meniscus concave lens, the twelfth lens is a biconvex lens, the thirteenth lens is a meniscus concave lens;
the second lens and the third lens form a first cemented lens, and a cemented surface of a double cemented lens faces to an aperture stop; the fourth lens and the fifth lens form a second cemented lens, and the cemented surface of the double cemented lens backs to the aperture stop; the eighth lens and the ninth lens form a third cemented lens, and the cemented surface of the double cemented lens faces to the aperture stop; the tenth lens and the eleventh lens form a fourth cemented lens, and the cemented surface of the double cemented lens backs to the aperture stop;
the eleventh lens, the twelfth lens, and the thirteenth lens are aspheric lenses; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, and the tenth lens are all spherical lenses.

6. The non-linear optical pumping detection apparatus according to claim 5 , wherein
an air interval between the sample and the first lens is a variable ranging from 50 to 200 millimeters;
a center thickness of the first lens is 4.678±0.1 mm, and an air interval between the first lens and the first cemented lens is 1.0±0.1 mm; a center thickness of the first cemented lens is 19.891±0.1 mm, an air interval between the first cemented lens and the second cemented lens is 9.986±0.1 mm; a center thickness of the second cemented lens is 21.593±0.1 mm, and an air interval between the second cemented lens and the sixth lens is 1.438±0.1 mm; a center thickness of the sixth lens is 10.128±0.1 mm, and an air interval between the sixth lens and the seventh lens is variable, ranging from 4.563±0.1 to 69.469±0.1 mm; a center thickness of the seventh lens is 2.0±0.1 mm, and an air interval between the seventh lens and the third cemented lens is 1.0±0.1 mm; a center thickness of the third cemented lens is 6.629±0.1 mm, and an air interval between the third cemented lens and the fourth cemented lens is variable, ranging from 1.0±0.1 to 33.162±0.1 mm; a center thickness of the fourth cemented lens is 17.276±0.1 mm, and an air interval between the fourth cemented lens and the twelfth lens is a variable, ranging from 0.930±0.1 to 25.0±0.1 mm; a center thickness of the twelfth lens is 6.614±0.1 mm, and an air interval between the twelfth lens and the thirteenth lens is variabl

Assignees

• Univ Jiangsu

Inventors

• Zhou Zhiqiang
• Cong Jiawei
• Tong Yanqun
• Chen Mingyang
• Lv liu
• Fu Yonghong
• Ren Naifei

Classifications

• G01N21/359 Primary

  using near infrared light · CPC title

• G02B5/005

  Diaphragms (for cameras G03B9/02) · CPC title

• G02B17/023

  for extending or folding an optical path, e.g. delay lines · CPC title

• G02B17/0668

  having non-imaging properties · CPC title

• G02B19/0014

  at least one surface having optical power · CPC title