CN108242762B - A tunable random laser chip based on double-sided PDMS wrinkle - Google Patents

Abstract

The present invention is an adjustable random laser chip based on double-sided PDMS folds, belonging to the technical field of random laser chips; the technical problem to be solved is to provide a low-cost, simple preparation, and convenient adjustable random laser chip; to solve the technical problem The adopted technical solution is: comprising a first PDMS sheet, a gain medium solution and a second PDMS sheet, the lower surface of the first PDMS sheet has a wrinkled structure, the upper surface of the second PDMS sheet has a wrinkled structure, and the gain medium solution is sandwiched between the first PDMS sheet and the first PDMS sheet. Between the PDMS sheet and the second PDMS sheet, and in contact with its wrinkled surface; the tunable random laser chip is pumped by the pumping laser, and one of the PDMS sheets is moved along the direction perpendicular to the wrinkle. The wrinkle period will change, and the wavelength of the outgoing laser will also change accordingly; the invention can be widely used in the field of random laser chips.

Description

A tunable random laser chip based on double-sided PDMS wrinkle

technical field

The invention is an adjustable random laser chip based on double-sided PDMS folds, belonging to the technical field of random laser chips.

Background technique

A traditional laser chip includes a gain medium and a resonator, where the resonator is usually composed of two mirrors that can generate coherent feedback. The random laser chip does not have a resonant cavity, and its feedback mechanism may have two types: one is that the light is partially reflected back to the interior of the medium by the interface between the random medium and the air, thereby forming feedback; the other is that the light beam forms a closed loop in the random medium , so as to play a feedback effect similar to that of a resonant cavity. For the traditional laser chip, scattering should be avoided as much as possible in the experiment, but the random laser chip is different, it uses the multiple scattering of light waves by random medium to form the laser. Therefore, the physical mechanisms of these two laser chips are completely different, which makes the random laser chip have some unique luminous characteristics.

To date, various types of microcavities have been developed in conventional laser chips, and although considerable efforts have been made in the optimization of microcavity design, precise fabrication of soft lithography processes and precise control of liquid flow rates still have Great challenge, adding enormous complexity in both manufacturing and operations. Recently, the fusion of optofluidics and random structures has provided a new avenue for on-chip random laser source integration. Due to the limited precision of soft lithography, Bhaktha et al. demonstrated an optofluidic random laser based on the folds of serpentine polydimethylsiloxane (PDMS) channels, which greatly reduces the need for high-standard fabrication techniques. Chen Xianfeng et al. used oxygen plasma to treat the surface of stretched PDMS, and the stretched PDMS could form wrinkles on its surface after the stress was released, and used PDMS wrinkles to generate random laser light. This further simplifies the preparation process and reduces the preparation cost.

Using PDMS folds to generate random lasers is a simple and effective method. The period of the wrinkle has an important influence on the properties of the laser, such as the wavelength. Chips prepared by using one PDMS wrinkled sheet and one PDMS flat sheet need to prepare many sheets of wrinkles of different periods during the experiment; during the operation, replacing the wrinkles of different periods will greatly increase the external influencing factors, and the experimental process becomes complicated and cumbersome. . Therefore, a chip with adjustable wrinkle period can be prepared, so as to achieve the purpose of generating a tunable random laser.

SUMMARY OF THE INVENTION

The present invention is an adjustable random laser chip based on double-sided PDMS folds, which overcomes the shortcomings of the prior art and provides a low-cost, simple preparation and convenient adjustable random laser chip.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a tunable random laser chip based on double-sided PDMS folds, comprising a first PDMS sheet, a gain medium solution and a second PDMS sheet, and the lower surface of the first PDMS sheet It has a wrinkled structure, the upper surface of the second PDMS sheet has a wrinkled structure, the gain medium solution is sandwiched between the first PDMS sheet and the second PDMS sheet, and is in contact with its wrinkled surface; the pump laser is used to pump the tunable random laser chip Pu, moving one of the PDMS sheets along the direction perpendicular to the folds, the period of the folds formed between the two PDMS sheets will change, and the wavelength of the outgoing laser will also change.

Further, the thickness of the PDMS sheet is 0.1 mm˜2 mm.

Further, the gain medium solution is a dye molecule solution or a quantum dot solution.

Compared with the prior art, the present invention has the following beneficial effects.

1. Using two wrinkled PDMS sheets, lasers of different wavelengths can be generated by changing the wrinkle period, which is fast and easy to operate.

2. It only needs to move one of the PDMS chips to generate lasers of different wavelengths, no need to replace chips, the operation process is simple, and it is less affected by external factors.

3. The problem that chips prepared by using a PDMS corrugated sheet and a PDMS flat sheet need to be prepared with different creasing periods is avoided, and the chip has the characteristics of low cost and simple preparation.

Description of drawings

FIG. 1 is a schematic cross-sectional structure diagram of the present invention.

In the figure, 1- the first PDMS sheet, 2- the gain medium solution, 3- the second PDMS sheet.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in FIG. 1 , a tunable random laser chip based on double-sided PDMS folds of the present invention includes a first PDMS sheet 1 , a gain medium solution 2 and a second PDMS sheet 3 . The lower surface of the first PDMS sheet 1 has a wrinkled structure, the upper surface of the second PDMS sheet 3 has a wrinkled structure, and the gain medium solution 2 is sandwiched between the first PDMS sheet 1 and the second PDMS sheet 3 and is in contact with its wrinkled surface; The tunable random laser chip is pumped by a pump laser. When the light formed by the scattering of light in the gain medium solution and the PDMS wrinkled surface is amplified enough to overcome the loss, laser light is generated, which moves along the direction perpendicular to the wrinkle. For a PDMS sheet, the wrinkle period formed between the two PDMS sheets will change, and the wavelength of the emitted laser will also change accordingly.

Example 1

The length of the first PDMS sheet 1 is 4 cm, the width is 4 cm, and the thickness is 0.1 mm. The lower surface of the first PDMS sheet 1 has a wrinkled structure, and the wrinkle period is 2 μm. Gain medium solution 2 was a 1 mM solution of Rhodamine 6G (R6G) in ethylene glycol. The length of the second PDMS sheet 3 is 4 cm, the width is 4 cm, and the thickness is 2 mm. The upper surface of the second PDMS sheet 3 has a wrinkled structure, and the wrinkle period is 2 μm.

Example 2

The length of the first PDMS sheet 1 is 3 cm, the width is 3 cm, and the thickness is 2 mm. The lower surface of the first PDMS sheet 1 has a wrinkled structure, and the wrinkle period is 1 μm. Gain medium solution 2 is a 2 μM solution of CdSe/ZnS quantum dots. The length of the second PDMS sheet 3 is 3 cm, the width is 3 cm, and the thickness is 0.12 mm. The upper surface of the second PDMS sheet 3 has a wrinkled structure, and the wrinkle period is 3 μm.

Although the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that form and detail may be made therein without departing from the spirit and scope of the invention as defined in the claims various changes on.

Claims (1)

1. A tunable random laser chip based on double-sided PDMS folds, characterized in that it comprises a first PDMS sheet (1), a gain medium solution (2) and a second PDMS sheet (3), the first PDMS sheet (1) ) has a wrinkled structure on the lower surface, the upper surface of the second PDMS sheet (3) has a wrinkled structure, and the gain medium solution (2) is sandwiched between the first PDMS sheet (1) and the second PDMS sheet (3), and is connected with it The wrinkled surfaces are in contact; the tunable random laser chip is pumped by the pump laser, and one of the PDMS sheets is moved along the direction perpendicular to the wrinkle. The thickness of the two PDMS sheets (1, 3) is 0.1 mm to 0.12 mm or 2 mm, and the gain medium solution (2) is a quantum dot solution.

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