KR101813971B1 - Photonics device for mode-locked laser based on black phosphorus and ring laser cavity including the same, method of manufacturing the photonics device - Google Patents

Abstract

An optical element for a mode-locking laser using a black phosphor includes: a core portion formed at the center in the longitudinal direction of the optical fiber to allow the laser to pass therethrough; A cladding portion surrounding the core portion and partially removing the core portion to expose the core portion along the longitudinal direction; And a black phosphor layer positioned on the removed core section and interacting with the laser to induce saturable absorption of the laser in the core section. Thus, it is possible to generate a high-quality laser pulse of high quality.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an optical element for a mode-locked laser using a black phosphor, a laser resonator including the optical element, and a method of manufacturing the optical element.

The present invention relates to an optical element for a mode-locked laser using a black phosphor, a laser resonator including the optical element, and a method of manufacturing the optical element. More particularly, the present invention relates to a mode- To a laser resonator including the optical element, and to a method of manufacturing the optical element.

Since the discovery of graphene in 2004, a variety of 2D nanomaterials and their application methods have been discovered and studied. Graphene has various optical properties including a high transmittance and a wide transmittance spectrum as well as various advantages such as toughness as a physical device and high charge mobility as an electronic device, and application research as an optical device material using the graphene has been made.

However, disadvantages such as a small bandgap and a low on / off ratio (ON / OFF RATIO) limit the use of graphene as a semiconductor, and the phase of the next-generation semiconductors, which was initially noted, has been considerably degraded.

Other 2D nanomaterials such as CHALCOGENIDE have been investigated and their potential as a next-generation semiconductor material has been explored, but apart from the bandgap, their electrical properties have either surpassed or matched graphene I could not give it.

Black phosphorus, on the other hand, is one of the phosphorus isotopes, which is a layered structure that can be as atomic as a graphene. Black is a next-generation semiconductor material that has been reported to overcome both the metal properties of graphene and the low charge mobility of chalcogenide, which are considered as factors that hinder semiconductor device characteristics.

However, since the reaction rate of black phosphorus in the atmosphere is too high to be stable, it is difficult to manufacture and operate semiconductor devices.

KR 10-1028803 B1

J. Sotor; G. Sobon1; W. Macherzynski; P. Paletko and K. M. Abramski, "Black phosphorus saturable absorber for ultrashort pulse generation ", Applied Physics Letters, 107, 051108 (2015)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an optical element for generating an ultrahigh speed mode locking laser using a black phosphor.

Another object of the present invention is to provide a laser resonator using an optical element using the black phosphor as a saturated absorber.

It is still another object of the present invention to provide a method for simply and rapidly manufacturing an optical element using the black phosphor.

According to an aspect of the present invention, there is provided an optical element for a mode locking laser using a black phosphor, the optical element including: a core portion formed at the center of the length of the optical fiber to allow a laser to pass therethrough; A cladding portion surrounding the core portion and partially removing the core portion to expose the core portion along the longitudinal direction; And a black phosphor layer positioned on the removed core section and interacting with the laser to induce saturable absorption of the laser in the core section.

In an embodiment of the present invention, the optical element may further include a protective layer formed on the black phosphor layer to prevent oxidation of the black phosphor layer.

In an embodiment of the present invention, the protective layer may be formed of a polymer compound.

In an embodiment of the present invention, the black layer may be formed as a single layer.

In an embodiment of the present invention, the black layer may be formed in multiple layers.

According to another aspect of the present invention, there is provided a laser resonator for generating a mode locking laser pulse, the wavelength resonator including a wavelength division multiplexer (WDM) connected to a laser generator, ; An amplifier for amplifying a laser beam transmitted from the wavelength division multiplexer; An isolator connected to the amplifier, the isolator preventing reverse flow of the laser; A coupler for branching the laser to output a part of the laser; An optical element for controlling a laser beam branched from the coupler; And a polarization controller (PC) connected to the optical element and controlling the polarization of the laser, wherein the optical element includes a core formed at the center of the optical fiber in the longitudinal direction to pass the laser, part; A cladding portion surrounding the core portion, the cladding portion partially removed along the longitudinal direction; And a black phosphor layer positioned on the surface of the cladding portion close to the lower core portion from which the cladding portion is removed and interacting with the laser to induce saturated absorption of the laser in the core portion.

In an embodiment of the present invention, the laser resonator can generate laser pulses having an intermediate wavelength in the 1530 nm to 1560 nm band.

In an embodiment of the present invention, the laser resonator may generate a laser pulse whose pulse width is between a few picoseconds (ps) and a few hundred femtoseconds (fs).

In an embodiment of the present invention, the optical element may further include a protective layer formed on the black phosphor layer to prevent oxidation of the black phosphor layer.

In an embodiment of the present invention, the protective layer may be formed of a polymer compound.

In an embodiment of the present invention, the black layer may be formed as a single layer.

In an embodiment of the present invention, the black layer may be formed in multiple layers.

According to another aspect of the present invention, there is provided a method of manufacturing an optical element, including: peeling a black phosphor layer; Removing a portion of a cladding portion surrounding the core portion of the optical fiber to expose the core portion along a longitudinal direction of the optical fiber; And transferring the blackened layer onto the exposed core.

In an embodiment of the present invention, the manufacturing method of the optical element may further include forming a protective layer formed of a polymer compound on the black layer.

In the embodiment of the present invention, the step of peeling the black layer may be a scotch tape method.

In the embodiment of the present invention, the step of transferring the blackened layer onto the exposed core part may take a scotch tape on which the thinly separated black layer is transferred, on the exposed core part.

In the embodiment of the present invention, in the step of transferring the blackened layer onto the exposed core portion, the scotch tape may be photographed several times.

In the embodiment of the present invention, the step of peeling the black layer may use a polymer stamping method.

In an embodiment of the present invention, the step of transferring the blackened layer onto the exposed core part may take a polymer stamp on which the thinly separated blackened layer is transferred onto the exposed core part.

In an embodiment of the present invention, the step of transferring the blackened layer onto the exposed core portion may take the polymer stamp several times.

According to the optical element for a mode-locking laser using the black phosphor, an ultra-high speed mode locking laser is implemented, and data processing speed and quality can be improved when applied to various communication devices. The optical element for a mode-locking laser using the black phosphor according to the present invention enables the interaction between the side-polishing optical fiber and the loss field of the black signal and the optical signal transferred thereon. In this small-mount reaction mode, the black layer is present in a place isolated from the direct direction of the optical signal, so that the protective layer made of the polymer compound can be put on the black line without excessive loss or scattering of the optical signal.

Since the protective layer of the polymer compound isolates the black phosphor which is easily oxidized in air from the oxidizing element such as oxygen, the black phosphor optical element can be stably operated even in a normal environment such as room temperature. In addition, since the small-mount operation, which is a general advantage of the small-mount reaction method, can obtain the necessary reaction with a relatively low-power optical signal, damage of the black phosphorus due to the high output laser can be prevented.

1 is a cross-sectional view of an optical element for a mode-locked laser using a black phosphor according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram showing saturation absorption characteristics of a black phosphor having a band gap structure.
3 is a graph showing an absorption spectrum of black phosphorus.
4 is a graph showing a change in nonlinear transmittance versus light output of an optical element for a mode locking laser using the black phosphor of the present invention.
5 is a configuration diagram of a laser resonator including an optical element for a mode locking laser using a black phosphor according to an embodiment of the present invention.
6 is a graph showing a pulse spectrum of a laser output from the laser resonator of FIG.
FIG. 7 is a graph showing a pulse train of a laser output from the laser resonator of FIG. 5;
8 is a graph showing the pulse width of the laser output from the laser resonator of FIG.
9 is a flowchart of a method of manufacturing an optical element for a mode locking laser using a black phosphor according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

1 is a cross-sectional view of an optical element for a mode-locked laser using a black phosphor according to an embodiment of the present invention.

An optical element 10 (hereinafter referred to as an optical element) for a mode locking laser using a black phosphor according to the present invention includes an optical fiber including a core portion 11 and a cladding portion 13 and a black phosphor layer 15).

On the other hand, black phosphorus has a very high charge mobility (about 300 to 1,000 cm ² / V · s) as well as on / off ratio (ON / OFF RATIO, ⁴ ~ 10 ⁵ ), showing remarkable properties. Recently, it is attracting much attention as a new next-generation semiconductor material.

In other words, since black is not only an excellent optical material to conform to graphene, but also possesses the characteristics of semiconductors, it shows applicability beyond graphene. However, since research as a semiconductor including a bandgap, which is intensively interested in the early stage, has been given priority, the study of optical characteristics has been relatively slow, and the application of black phosphorus as a practical optical element is relatively inexperienced . In addition, it is vulnerable to deterioration such as oxidation compared with graphene, and is vulnerable to optical damage, which is a major obstacle to research in this field.

The present invention solves the above problem and implements an ultrahigh speed mode locking laser by combining the nonlinear light absorption of the black phosphor and the optical signal amplification of the optical fiber laser resonator.

The core 11 is formed at the center of the optical fiber in the longitudinal direction (x-axis direction, which is the laser transmission direction), and allows the laser to pass therethrough. The core portion 11 is formed of a material having a higher refractive index than the cladding portion 13.

The cladding portion 13 surrounds the core portion 11 and is laterally polished to remove a part thereof. Accordingly, a groove 14 is formed in the cladding portion 13, and the core portion 11 is partially exposed along the longitudinal direction (x-axis direction) of the optical fiber.

The blackened layer 15 is located on the core portion 11 from which the cladding portion 13 is removed and induces saturation absorption of the laser in the core portion 11 by virtue of the virtualization with the laser. The black phosphor layer 15 may be formed as a single layer or a multilayer.

The laser is transmitted through the core portion 11 extending along the x-axis direction. Since the core portion 11 is not cut off by the black layer 15, the laser is continuously transmitted without being blocked by the black layer 15. The laser beam transmitted along the core portion 11 is guided by the refractive index difference between the core portion 11 and the cladding portion 13.

A portion of the guided laser reacts with the blackening layer 15 to form a laser pulse. That is, as the average refractive index of the cladding portion 13 decreases, the mode field spreads widely. For example, the cladding portion 13 filled with silica having a refractive index of about 1.5 is filled with air having a refractive index of 1 by the removed groove 14, and the average refractive index of the portion is lowered. As a result, the mode field is widened.

Here, the mode field widely spread in the portion polished by the groove 14 and the black phosphor layer 15 react with each other to form a laser pulse. The tail portion of the widened mode field is called the small mount.

The black phosphor layer 15 is not thermally damaged by the small-mount operation in which only a part of the laser reacts with the black phosphor layer 15. [ The raw material burnt in the core portion 11 even at an optical intensity of about 15 dBm is stably operated without burning even at a higher optical intensity. That is, since the weaker black layer 15 is not easily damaged, the black layer 15 can be used semi-permanently.

As a result, it is possible to stabilize the thermally weak black layer 15 even in the high-power laser operation through the small-mount operation method. The laser pulse formed by the blackened layer 15 and guided is transmitted along the x-axis direction on the core portion 11. [

FIG. 2 is a conceptual diagram showing saturation absorption characteristics of a black phosphor having a band gap structure.

Referring to FIG. 2, black is a saturable absorption material that absorbs light of weak intensity, and passes light of strong intensity when saturated. In addition, since it has a high nonlinearity, the pulse size can be minimized, and a high quality pulse can be generated.

As shown in FIG. 2 (a), the black phosphor has a certain bandgap and absorbs only energy above the bandgap. The bandgap has a semiconducting property, and the bandgap can be changed within a range of 0.3 to 2.0 eV depending on the number of layers, that is, the thickness of the black phosphor layer 15.

As shown in FIG. 2 (b), when the amount of photons to be absorbed is small, the electrons generate holes in the valence electron band and are excited to a specific position of the conduction band corresponding to the wavelength of the photon. The generated holes and electrons are gradually charged from the ends of the electron band and the conduction band, so that the width of the energy band becomes wider and the photon having the same wavelength can not be absorbed.

That is, as shown in FIG. 2 (c), when the amount of photons is large enough, the generated carriers fill the energy state and the energy state is not excited because the electrons are no longer blocked by the Paulownia principle of the occupied carriers State. This explains energy saturation absorption by the black phosphorus.

On the other hand, it is also possible to generate laser pulses using mechanical on / off switching and Q switching. However, in this case, the reproducibility of the generated laser pulse is lowered and the width of the pulse is too wide to form a pulse of femtoseconds (10 ^-15 seconds).

On the other hand, when carbon nanotubes (CNTs) are used, since the carbon nanotubes have a high specific surface area, the carbon nanotubes cohere to each other and the nonlinearity thereof is lowered. And, the regeneration time of the carbon nanotubes is too long as 500 fs or less. Further, it is difficult to arrange the carbon nanotubes, and it is difficult to control the twisting and diameter of the carbon nanotubes.

As a result, it is difficult to control the band gap of the carbon nanotubes. Therefore, the operating bandwidth of the carbon nanotubes is limited. Therefore, in order to solve this problem, it is necessary to increase the operating bandwidth by mixing the different types of carbon nanotubes. However, in this case, the efficiency of mode locking is lowered. Also, graphene can solve the non-linearity of carbon nanotubes, but a low on / off ratio can be a problem.

On the other hand, black phosphorus is one of the phosphorus isotopes, which is a layered structure that can be as atomic as a graphene. Blackness can overcome both the metal properties of graphene, which is a factor that hinders semiconductor device characteristics, and the low charge mobility of chalcogenide.

Black phosphor has both a very high charge mobility and an excellent on-off ratio. Referring to FIG. 3, in addition to the high transmittance comparable to graphene, it has a broad transmission spectrum (including 1550 nm band) have.

On the other hand, black grains are more vulnerable to the environment than graphenes, and when irradiated with a laser, the energy of absorbed light accelerates oxidation, resulting in rapid deterioration, which is practically limited. When used as a saturated absorber, a common method is to insert a piece of black dust between the cores of the optical fiber in a direct-acting manner, which can be exposed to high energy and be damaged, There is a fear of deterioration due to the above.

In order to solve such a problem, the present invention is applied to an indirect operation method using a small-sized package. Specifically, one side of the cladding portion 13 is D-shaped by side grinding so that the core portion 11 and the cladding portion 13 existing at the boundary between the core portion 11 and the cladding portion 13, Expose the small mount.

If black pieces are stuck on the side-polished optical fiber, the attenuation of the optical signal inside the core portion 11 can be induced by the small-sized absorbing action of these pieces. The nonlinear optical absorption of the black light and the optical signal amplification of the optical fiber laser resonator are combined to complete the ultrahigh speed mode locking laser.

The relative transmittance to the light output was measured to demonstrate the optical nonlinearity in the case of the completed device by attaching the pieces of black phosphor to the side polished optical fiber. As a result, the saturation peak power density distribution saturated at about 12.5 MW / cm ² was recorded as shown in FIG. 4, and the modulation depth of about 3.31% was proved to be a nonlinear saturable absorber .

On the other hand, since the reaction rate in the air is too high to be stable, the optical element 10 has a protective layer (not shown) formed on the black layer 15 to isolate the black layer 15 from external elements Time). The protective layer isolates and protects the easily oxidizable black phosphorus from air or moisture which is a factor of oxidation.

The protective layer may be formed of a polymer compound. The polymer compound may be formed by curing a single material or by curing a mixture of single materials. The protective layer may be formed of, for example, polydimethylsiloxane (PDMS).

Accordingly, in the optical element according to the present invention, the propagation path of the optical signal is isolated from the thickness of the synthetic film, thereby avoiding scattering caused thereby. In addition, since the optical element is activated by the action of a part of the optical signal using a small-sized package, the possibility of damage to the material is reduced, and a protective layer is applied to the black phosphor which is easily oxidized on the air to isolate it from the air.

5 is a configuration diagram of a laser resonator including an optical element for a mode locking laser using a black phosphor according to an embodiment of the present invention.

The laser resonator 1 according to the present embodiment applies the optical element 10 for a mode locking laser using the black phosphor shown in Fig. 1 as a saturated absorption element of the laser resonator 1. The structure of the laser resonator 1 shown in Fig. 5 is merely an example, and it is possible to omit, add, and so on components as needed.

5, the laser resonator 1 converts the energy of the laser generated from the laser generator 2 into a laser of a desired wavelength in the amplifier 40, To generate a laser pulse. Each of the components of the laser resonator 1 is connected to an optical fiber 3 and may include a wavelength division multiplexer (WDM) 30, an amplifier 40, an isolator 50, A coupler 60, an optical element 10 for a mode locking laser using a black phosphor, and a polarization controller (PC).

The optical fiber 3 includes a core portion 11 through which a laser is passed and a cladding portion 13 surrounding the core portion 11. For example, the optical fiber 3 may be a single mode fiber (SMF), and the remaining optical fibers connected with the structures may be wound according to a necessary space.

The wavelength division multiplexer 30 is connected to the laser generator 2 and combines the laser output from the laser generator 2 and the laser circulating through the resonator 1 into one optical signal. The laser generator 2 may be a pump laser diode and may provide a laser of 980 nm or 1410 nm.

The amplifier 40 amplifies the laser in the resonator 1 using the energy of the laser output from the laser generator 2 transmitted from the wavelength division multiplexer 30. The laser used in the laser generator 2 is mainly a semiconductor laser and a solid laser can be used. Examples of the laser include Ruby, Nd: YAG (neodymium-doped yttrium aluminum garnet, Nd: Y3Al5O12, , Nd: Glass (Neodymium glass), or Ti: Sapphire.

In other words, the optical energy amplified by the amplifier 40 using the energy transmitted from the laser generator 2 forms a continuous wave (CW) by circulating the resonator 1, The laser generates a laser pulse by saturable absorption with the optical element 10 and the generated laser pulse is repeatedly amplified by the amplifier 40 to generate a laser pulse of high output . For example, an EDFA (Er-doped fiber amplifier) may be used as the amplifier 40.

The isolator 50 is connected to the amplifier 40 and prevents the laser from flowing backward. That is, the isolator 50 controls the laser resonator 1 so that the laser flows only in one direction.

The coupler 60 branches the laser to output a part of the laser. For example, a laser of 10% may be output by branching at a ratio of 90:10, and a laser of 90% may be transmitted to the optical element 10.

The laser resonator 1 may further include a polarization controller (PC) 70 connected to the optical element 10 to adjust the polarization of the laser, and the like.

The optical element 10 may proceed in substantially the same configuration as the optical element 10 in Fig. Therefore, the same constituent elements as those of the optical element 10 of Fig. 1 are denoted by the same reference numerals, and repeated description is omitted.

The optical element 10 partially removes the cladding portion 13 in a D-shaped cross section through side polishing of the cladding portion 13 of the optical fiber 3, Thereby exposing the small mount existing at the boundary between the portion 11 and the cladding portion 13.

If black pieces are stuck on the side-polished optical fiber, the attenuation of the optical signal inside the core portion 11 can be induced through the small-sized absorbing action of these pieces. That is, the cladding portion 13 is removed to form a monolayer or multi-layered black phosphorus layer 15 which is peeled off on the exposed core portion 11 to control the laser pulse. Further, a protective layer (not shown) may be formed on the black phosphor layer 15 to protect the black phosphor layer 15 from external elements to prevent oxidation.

The nonlinear light absorption of black in the optical element 10 and the optical signal amplification of the optical fiber laser resonator are combined to complete an ultrahigh speed mode locking laser.

The results of implementing the laser resonator 1 according to this embodiment are shown in FIGS. 6 to 8. FIG. 6 is a graph showing a pulse spectrum of a laser output from the laser resonator of FIG. FIG. 7 is a graph showing a pulse train of a laser output from the laser resonator of FIG. 5; 8 is a graph showing the pulse width of the laser output from the laser resonator of FIG.

Referring to FIGS. 6 to 8, the laser pulse output from the optical element 10 has an intermediate wavelength of about 1555 nm, shows a repetition rate of about 8.889 MHz, and shows a pulse duration of about 1.09 ps.

Accordingly, the mode locking laser pulse can be implemented by adding a saturated absorption element using a black phosphor in the optical fiber laser resonator. In addition, it has been confirmed that the optical nonlinearity of a black line which can be operated by a small-mount operation is applied to an actual device, and that a protective layer for preventing black oxidation does not interfere with pulse implementation.

Unlike graphene, black phosphorus used in the present invention is not sensitive to the number of layers, so that all processes such as physical peeling and transfer can be easily performed at room temperature, minimizing the possibility of damage to materials that may occur during operation through small- can do.

9 is a flowchart of a method of manufacturing an optical element for a mode locking laser using a black phosphor according to an embodiment of the present invention.

In the method of manufacturing an optical element for a mode locking laser using a black phosphor according to the present embodiment, the same constituent elements as those of the optical element 10 of Fig. 1 are denoted by the same reference numerals and repeated explanation is omitted.

Referring to FIG. 9, in the method of manufacturing an optical element for a mode locking laser based on a black phosphor according to the present embodiment, a black phosphor layer is first peeled (step S10). For example, a monolayer or multi-layered black phosphorus layer is peeled from a bulk black phosphor element.

In one embodiment, the black layer can be stripped from the bulk black element using a Scotch tape method. In another embodiment, the black phosphor layer can be peeled off from the bulk black phosphor element using a polymer stamping method. In the polymer stamping method, a polymer compound stamp such as PDMS (polydimethylsiloxane) can be used.

On the other hand, in the optical fiber including the core portion 11 and the cladding portion 13 surrounding the core portion 11, the cladding portion 13 is side-polished to remove a part thereof. Thus, a part of the cladding part 13 is removed so that a D-shaped groove 14 is formed in a side view, and the core part 11 extends along a longitudinal direction of the optical fiber, (Step S30).

Then, the cladding portion 13 is removed, and the peeled black layer is transferred onto the exposed core portion 11 (Step S50). In the present invention, the peeled black can be transferred directly onto the polished optical fiber at room temperature.

In one embodiment, when the black layer is peeled off by a Scotch tape method, a scratched tape on which a thinly peeled black layer has been transferred is dipped onto the exposed core part one or more times to transfer the black layer.

In another embodiment, when the black layer is peeled by the polymer stamping method, the polymer stamping to which the thinly peeled black layer has been transferred is once or several times stamped on the exposed core portion to transfer the black layer.

Further, the method may further include forming a protective layer formed of a polymer compound on the black layer (step S70). It is possible to form an optical element capable of operating in air by isolating and protecting the black phosphorus, which is easily oxidized, from the air or moisture which is a factor of oxidation by forming the protective layer.

The optical element according to the present invention uses a black material whose value is approximately 10 ² times higher than that of a carbon material having a relatively low on / off ratio, and thus can be applied to a semiconductor device, Can be manufactured in a simple process at room temperature without using special equipment such as dispersion and spray.

Accordingly, it is possible to dispense with processes that are harmful to the environment and human body, such as the use of an organic solvent required for dispersion, and it is possible to perform physical separation immediately without special equipment, and the quality of the peeled material is relatively insignificant, . In addition, the precision required to be transferred onto the core having a size of 10 탆 is not required, so that a simple and quick process is possible, and the damage of the material due to the optical signal can be reduced by the saturation absorption phenomenon through the small mounting action.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. You will understand.

With a direct bandgap that varies with adjustable thickness, black is a suitable material for the absorption and emission of optical signals, and is attracting attention as one of the next-generation semiconductor materials useful for photonics and optoelectronics. The present invention can enhance the applicability of black phosphorus in the photon field by applying a protective layer without scattering or additional loss of optical signal due to the solid oxidation problem of black phosphorus. The optical device thus manufactured is applied to a laser resonator to generate laser pulses of several hundred femtoseconds (fs) at a picosecond (ps), which can be used in various fields such as communication and medical devices.

10: Optical element for mode-locked laser using black phosphor
11: core part
13: cladding portion
14: Home
15: Black Phosphorus layer
1: laser resonator
2: Laser generator
3: Fiber
30: Wavelength Division Multiplexer
40: amplifier
50: Isolator
60: Coupler
70: polarization controller

Claims (20)

A core portion formed at the center of the optical fiber in the longitudinal direction to allow the laser to pass therethrough;
A cladding portion surrounding the core portion and partially removing the core portion to expose the core portion along the longitudinal direction;
A black phosphor layer positioned on the core portion from which the cladding portion is removed and interacting with the laser to induce saturable absorption of the laser in the core portion; And
And a protective layer formed on the black phosphor layer to prevent oxidation of the black phosphor layer.
delete The method according to claim 1,
Wherein the protective layer is formed of a polymer compound.
The method according to claim 1,
Wherein the black layer is formed as a single layer.
The method according to claim 1,
Wherein the black phosphor layer is formed in a multilayered structure.
CLAIMS 1. A laser resonator in which each structure is connected with an optical fiber to generate a mode locking laser pulse,
A Wavelength Division Multiplexer (WDM) coupled to a laser generator;
An amplifier for amplifying a laser beam transmitted from the wavelength division multiplexer;
An isolator connected to the amplifier, the isolator preventing reverse flow of the laser;
A coupler for branching the laser to output a part of the laser;
An optical element for controlling a laser beam branched from the coupler; And
And a polarization controller (PC) connected to the optical element and controlling the polarization of the laser,
Wherein the optical element comprises: a core portion formed at the center of the optical fiber in the longitudinal direction to allow the laser to pass therethrough; A cladding portion surrounding the core portion, the cladding portion partially removed along the longitudinal direction; A black phosphor layer positioned on a surface of the cladding portion close to the lower core portion from which the cladding portion is removed and interacting with the laser to induce saturated absorption of the laser in the core portion; And a protective layer formed on the black phosphor layer to prevent oxidation of the black phosphor layer.
The method according to claim 6,
Wherein the intermediate wavelength produces a laser pulse in the 1530 nm to 1560 nm band.
The method according to claim 6,
A laser resonator, wherein the pulse width is in the range of a few picoseconds (ps) to a few hundred femtoseconds (fs).
delete The method according to claim 6,
Wherein the protective layer is formed of a polymer compound.
The method according to claim 6,
Wherein the black layer is formed as a single layer.
The method according to claim 6,
Wherein the black phosphor layer is formed in a multilayered structure.
Peeling the Black Phosphorus layer;
Removing a portion of a cladding portion surrounding the core portion of the optical fiber to expose the core portion along a longitudinal direction of the optical fiber;
Transferring the blackened layer onto the exposed core; And
And forming a protective layer made of a polymer compound for preventing oxidation of the black layer on the black layer.
delete 14. The method of claim 13, wherein the step of peeling the black-
A method of manufacturing an optical element for a mode-locked laser using a black phosphor by using a scotch tape method.
16. The method of claim 15, wherein transferring the blackened layer onto the exposed core comprises:
A method for manufacturing an optical element for a mode locking laser using a black phosphor, wherein a scotch tape on which a thinly peeled black layer is transferred is photographed on the exposed core portion.
17. The method of claim 16, wherein the step of transferring the blackened layer onto the exposed core comprises:
The method of manufacturing an optical element for a mode-locked laser using a black phosphor to take the scotch tape several times.
14. The method of claim 13, wherein the step of peeling the black-
A method of manufacturing an optical element for a mode-locking laser using a black stain using a polymer stamping method.
19. The method of claim 18, wherein the step of transferring the blackened layer onto the exposed core comprises:
A method for manufacturing an optical element for a mode lock laser using a black phosphor, wherein a polymer stamp on which a thinly peeled black layer is transferred is photographed on the exposed core portion.
The method of claim 19, wherein transferring the blackened layer onto the exposed core comprises:
A method for manufacturing an optical element for a mode-locked laser using a black phosphor, wherein the polymer stamp is photographed several times.

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