KR20070097671A - A microwave generator using optical fiber laser incorporating a ultra-narrow bandpass filter - Google Patents

Abstract

A microwave signal generator using an optical fiber laser source based on an ultra-narrow band pass filter is provided to easily control a resonant wavelength and to utilize an optical fiber grid based laser and a phase transition optical fiber grid having an ultra-narrow bandwidth. A microwave signal generator using an optical fiber laser source based on an ultra-narrow band pass filter(50) comprises the followings: a pump laser diode generating a signal having a predetermined wavelength; a wavelength division optical coupler connected with the pump laser diode to divide or combine the signal, and then input the divided or combined signal to a resonator; a gain medium(30) excited by the signal to generate an amplified optical signal of high wavelength; the ultra-narrow band pass filter filtering the optical signal passing through the gain medium, through an ultra-narrow bandwidth; a circulator(40) formed between the gain medium and the ultra-narrow band pass filter to rotate the optical signal and remove a reflected signal in the ultra-narrow band pass filter; a filter(70) for a variable mirror disposed between the gain medium and the wavelength division optical coupler, to generate an optical fiber laser source by filtering the optical signal having the ultra-narrow bandwidth in a predetermined wavelength band; and a photoelectric converter(80) converting the optical fiber laser source into an electric signal.

Description

Microwave Generator Using Optical Fiber Laser Incorporating a Ultra-narrow Bandpass Filter

1 is a configuration diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based fiber laser light source according to a first embodiment of the present invention.

2 is a block diagram illustrating a microwave signal generator using a ultra narrow band bandpass filter based semiconductor laser light source according to a second embodiment of the present invention.

3 is a block diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based fiber laser light source according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based semiconductor laser light source according to a fourth embodiment of the present invention.

5 is a detailed view of a phase shift optical fiber grating as an example of an ultra narrowband transmission filter according to the first and third embodiments of the present invention.

6 is a diagram illustrating a transmission spectrum of an ultra narrow band bandpass filter and a filter for a variable mirror according to the first to fourth embodiments of the present invention.

FIG. 7 is a view illustrating an electrical signal outputted by an optical fiber or a semiconductor laser light source transmitted to a photoelectric converter according to the first to fourth embodiments of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave signal generator using a fiber laser light source, and more specifically, to an optical fiber laser light source having a single longitudinal mode frequency using an ultra narrow band bandpass filter and using the microwave signal. The present invention relates to a microwave signal generator using an ultra narrow band bandpass filter-based fiber laser light source for generating a signal.

A light source for use in optical communication is an optical source that operates at a single longitudinal mode frequency because it is susceptible to noise due to the instability of the signal itself and to other frequency components as it passes over a long distance optical fiber. Much research is being done on this.

The conventional technique uses a single longitudinal mode fiber laser by removing high frequency components by using an erbium-doped optical fiber as a saturable absorber that absorbs light without excitation as a pumping light source. ) Although the light source is implemented, it cannot be used as a microwave signal generator, and only a laser light source having a low output (<10 dB) can be realized since the erbium-doped fiber absorber no longer functions at a high output. The disadvantage is that the output is difficult to obtain or the structure is complicated, so the actual implementation is not easy.

In addition, several Sagnac Loop Filters were connected in series to implement a filter with narrow bandwidth, and then a single frequency fiber laser light source was implemented using a fiber laser resonator. The application was not presented and it is difficult and complicated to implement by connecting several filters in series.

All of the above-described conventional techniques operate at a single wavelength, so that wavelength shift is not easy and a technique for applying a fiber laser light source having a single longitudinal mode frequency to a microwave signal generator has not been proposed. In addition, no microwave signal generator using a phase-shifted fiber grating with an ultra narrow bandwidth and a fiber grating-based laser is presented.

In order to solve the above problems, an object of the present invention is to implement a single wavelength or multi-wavelength fiber laser light source operating in an effective single longitudinal mode and to implement a microwave signal generator based thereon.

In addition, an object of the present invention is to implement a microwave signal generator based on a fiber laser light source of high-performance easy to adjust the resonance wavelength, simple implementation. In particular, an object of the present invention is to implement a microwave signal generator using a phase shift fiber grating having an ultra narrow bandwidth and a fiber grating based laser.

Microwave signal generator using a fiber laser light source for achieving the above object comprises a pump laser diode for generating a signal having a predetermined wavelength; A wavelength division optocoupler connected to the pump laser diode to split or couple the signal to a resonator; A gain medium activated by the signal to produce a high wavelength amplified optical signal; An ultra narrow band bandpass filter for filtering the optical signal passing through the gain medium to an ultra narrow bandwidth; A circulator formed between the gain medium and the ultra narrow band bandpass filter to rotate the optical signal and remove a reflected signal from the ultra narrow band band pass filter; A variable mirror filter formed between the gain medium and the wavelength division optical coupler to generate an optical fiber laser light source by filtering an optical signal having an ultra narrow bandwidth at a predetermined wavelength band; And a photoelectric converter for converting the optical fiber laser light source into an electrical signal.

In addition, the object is a semiconductor amplifier for amplifying a predetermined signal; An ultra narrow band bandpass filter for filtering the signal amplified by the semiconductor amplifier to an ultra narrow bandwidth; A circulator formed between the semiconductor amplifier and the ultra narrow band bandpass filter to rotate a signal having the ultra narrow bandwidth and remove a reflected signal from the ultra narrow band band pass filter; A variable mirror filter for generating a semiconductor laser light source by filtering a signal having an ultra narrow bandwidth amplified by the semiconductor amplifier through the circulator in a predetermined wavelength band; And it can also be achieved by a microwave signal generator using a semiconductor laser light source, characterized in that it comprises a photoelectric converter for converting the semiconductor laser light source into an electrical signal.

Furthermore, a microwave signal generator using a fiber laser light source for achieving the above object includes a pump laser diode for generating a signal having a predetermined wavelength; A wavelength division optocoupler connected to the pump laser diode to split or couple the signal to a resonator; A gain medium activated by the signal to produce a high wavelength amplified optical signal; An ultra narrow band bandpass filter for filtering the optical signal passing through the gain medium to an ultra narrow bandwidth; A circulator having three ports, the first port being connected to the ultra narrow band bandpass filter to transmit an optical signal having the ultra narrow bandwidth; A variable mirror filter connected to a second port of the circulator to generate an optical fiber laser light source by filtering an optical signal having an ultra narrow bandwidth transmitted to the second port in a predetermined wavelength band; An optical coupler connected between the wavelength division optical coupler and the third port of the circulator and outputting the optical fiber laser light source by dividing the optical fiber laser light at a predetermined ratio; And a photoelectric converter converting the optical fiber laser light source output from the optical coupler into an electrical signal and outputting the electrical signal.

In addition, the object is a semiconductor amplifier for amplifying a predetermined signal; An ultra narrow band bandpass filter for filtering the signal amplified by the semiconductor amplifier to an ultra narrow bandwidth; A circulator having three ports, the first port being connected to the ultra narrowband bandpass filter to transmit a signal having the ultra narrow bandwidth; A variable mirror filter connected to a second port of the circulator to filter an optical signal having an ultra narrow bandwidth transmitted to the second port in a predetermined wavelength band to generate a semiconductor laser light source; An optical coupler connected between the semiconductor amplifier and a third port of the circulator and outputting the semiconductor laser light source by dividing the semiconductor laser light source by a predetermined ratio; And a microwave signal generator using a semiconductor laser light source including a photoelectric converter converting the optical fiber laser light source output from the optical coupler into an electrical signal and outputting the electrical signal.

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

First embodiment

1 is a configuration diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based fiber laser light source according to a first embodiment of the present invention.

Referring to FIG. 1, a microwave signal generator using an ultra narrow band pass-through filter-based optical fiber light source includes a pump laser diode (10), a wavelength division optical coupler (20), a gain medium (30), and a circulator (circulator). 40, a linear resonator and a photoelectric converter 80 composed of an ultra narrow band bandpass filter 50, a polarization controller 60, and a filter 70 for a variable mirror.

The gain medium 30 uses erbium (Er) or ytterbium (Yb) -doped optical fibers, silica-based general single mode optical fibers, nonlinear optical fibers, photonic crystal optical fibers or bismuth optical fibers, and to activate them. The pump laser diode 10 is used. That is, the 980 nm or 1480 nm wavelength signal from the pump laser diode 10 activates the gain medium 30 to generate an Amplified Spontaneous Emission (ASE) signal in the high wavelength region (about 1500 to 1600 nm). The optical signal may be amplified.

The wavelength division optical coupler 20 serves to separate or combine the signal from the pump laser diode 10 and the ASE signal generated in the high wavelength region (about 1500 to 1600 nm).

Resonator mirrors are configured on both sides of the gain medium 30, which are used to generate a laser light source by inducing a round trip of an optical signal. In FIG. 1, a left side of the gain medium 30 is used. The first mirror is configured using the circulator 40 and the ultra narrow band bandpass filter 50, and the second mirror is configured on the right side of the gain medium 30 using the variable mirror filter 70. A linear resonator for inducing a laser phenomenon is constructed.

That is, the signal of the pump laser diode 10 activates the gain medium 30 through the wavelength division coupler 20 to induce an optical signal, and the induced optical signal is the first and second mirrors on both sides of the gain medium 30. The reciprocating motion of the gain medium 30 is caused by the optical fiber laser phenomenon.

The circulator 40 is an element that allows the optical signal to be delivered in the order of 1-> 2-> 3-> 1 port and removes the reflected signal from the ultra narrow band bandpass filter 50. Do it.

An ultra narrow band bandpass filter 50 is formed between the second port and the third port of the circulator 40 to filter the optical signal to the ultra narrow bandwidth. The ultra narrow band bandpass filter 50 may include a phase shift fiber grating, a micro electro mechanical system (hereinafter referred to as a "MEMS element"), a fabric-perot filter, or a sagnag loop ( Sagnac loop filter can be used. The optical signal passing through the ports 1-> 2 of the circulator 40 passes through the ultra narrowband bandpass filter 50 and is transmitted to the gain medium 30 through the 3-> 1 port again. At this time, the bandwidth of the optical fiber laser light source has the ultra narrow bandwidth as shown in FIG.

The optical signal having the ultra narrow bandwidth is again formed through the gain medium 30 and the optical fiber laser light source is formed while repeating a round trip in which the bandwidth is filtered and reflected back from the variable mirror filter 70. The variable mirror filter 70 may use an optical fiber grating, a chirped optical fiber grating, or a bulk mirror as a reflective filter, and may easily change the output wavelength since the bandwidth may be varied (see FIG. 6). ).

The polarization controller 60 controls the polarization state of the laser output to stabilize the laser output that may be unstable by the polarization.

The photoelectric converter 80 converts the optical fiber laser light source generated through the linear resonator into an electrical signal to generate a microwave signal.

Second embodiment

2 is a block diagram illustrating a microwave signal generator using a ultra narrow band bandpass filter based semiconductor laser light source according to a second embodiment of the present invention.

Referring to FIG. 2, a microwave signal generator using an ultra narrowband bandpass filter based semiconductor laser light source uses a semiconductor amplifier 30 ′ instead of a gain medium 30 using an erbium-doped fiber amplifier in the configuration diagram of FIG. 1. , Except that the pump laser diode 10 and the wavelength division optical coupler 20 are removed. That is, when the semiconductor amplifier is used, the pump laser diode 10 and the wavelength division optical coupler 20 used in FIG. 1 are not used because the optical signal amplified by the semiconductor amplifier is generated.

The microwave signal generator using the ultra narrow band bandpass filter based semiconductor laser light source according to the second embodiment of the present invention is a semiconductor amplifier 30 ', a circulator (40), the ultra narrow band bandpass filter 50, a polarization controller A linear resonator and a photoelectric converter 80 composed of a 60 and a filter 70 for a variable mirror.

The optical signal of the semiconductor amplifier 30 'is filtered to the ultra narrow bandwidth by the ultra narrow band bandpass filter 50 via the circulator 40, and is then again filtered by the variable mirror filter 70 through the semiconductor amplifier 30'. A round trip is made which is transmissive and reflected again. Hereinafter, a person skilled in the art to which the present invention pertains may easily understand FIG. 2 as a description of the configuration of FIG. 1, and thus a detailed description of FIG. 2 will be omitted.

Third embodiment

3 is a block diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based fiber laser light source according to a third embodiment of the present invention.

Referring to FIG. 3, the microwave signal generator using the ultra narrow band pass-through filter-based optical fiber light source according to the second embodiment of the present invention includes a pump laser diode (100), a wavelength division optical coupler (200), and a gain medium. Ring 300, isolator 400, ultra narrow band bandpass filter 500, polarization regulator 600, circulator 700, variable mirror filter 800 and optocoupler 900 (Ring) resonator and photoelectric converter (1000).

The gain medium 300 uses erbium (Er) or ytterbium (Yb) -doped optical fibers, silica-based general single mode optical fibers, nonlinear optical fibers, photonic crystal optical fibers, or bismuth optical fibers, and to activate them. The pump laser diode 100 is used.

The wavelength division optical coupler 200 serves to separate or combine the signal of the pump laser diode 100 and the ASE signal generated in the high wavelength region (about 1500-1600 nm).

The isolator 40 serves to remove the reflected signal of the ultra narrow band bandpass filter 500.

The ultra narrow band pass-through filter 500 filters the bandwidth of the optical fiber laser light source into the ultra narrow bandwidth, and is a phase shift fiber grating, MEMS device, fabric-perot filter, or Sagnac loop filter. Can be used.

The polarization controller 600 filters the optical signal in a predetermined direction, and adjusts it to extract only the optical signal in a desired direction.

The circulator 40 is an element that allows the optical signal to be transmitted in the order of 1-> 2-> 3 port.

The variable mirror filter 800 is connected to the two ports of the circulator 40 and transmits the optical signal of the ultra narrow bandwidth, which has entered the two ports through one port, once again to filter the bandwidth to three ports. The variable mirror filter 800 may use an optical fiber grating, a chirped optical fiber grating, or a bulk mirror as a reflective filter, and may easily change the output wavelength since the bandwidth may be varied (see FIG. 6). ).

The optical coupler 900 is a device for dividing an optical signal at a constant ratio. In the case of FIG. 3, 10% is output and 90% is circularly moved within the ring resonator.

The photoelectric converter 1000 generates a microwave signal by converting a 10% optical fiber laser light source output through the ring resonator into an electric signal.

Referring to FIG. 3, the signal generated by the pump laser diode 100 generates an optical signal by activating the gain medium 300 through the wavelength division optical coupler 200 and through the isolator 400. Band bandpass filter 500 is passed.

The optical signal having the ultra narrow bandwidth by the ultra narrow band band pass filter 500 is stabilized in the polarization state through the polarization controller 600, and passes through the port 1 of the circulator 700 through the port 2 and the variable mirror. Is delivered to the filter 800. In addition, the bandwidth is filtered again by the variable mirror filter 800, and the optical signal is transmitted to the gain medium 300 again through the port 3 of the circulator 700 to be round tripped to the optical fiber laser light source. Will form.

In this case, a 10% optical fiber laser light source output is transmitted to the photoelectric converter 1000 through the optical coupler 900 to generate a microwave signal.

Fourth embodiment

FIG. 4 is a diagram illustrating a microwave signal generator using an ultra narrow band bandpass filter based semiconductor laser light source according to a fourth embodiment of the present invention.

Referring to FIG. 4, a microwave signal generator using an ultra narrowband bandpass filter based semiconductor laser light source uses a semiconductor amplifier 30 ′ instead of a gain medium 30 using an erbium-doped fiber amplifier in the configuration diagram of FIG. 3. , Except that the pump laser diode 10 and the wavelength division optical coupler 20 are removed. That is, when the semiconductor amplifier is used, the pump laser diode 10 and the wavelength division optical coupler 20 used in FIG. 1 are not used because the optical signal amplified by the semiconductor amplifier is generated.

The microwave signal generator using the ultra narrow band pass-through filter-based semiconductor laser light source according to the fourth embodiment of the present invention includes a semiconductor amplifier 300 ', an isolator 400, an ultra narrow band pass filter 500, and a polarization controller. 600), a ring resonator and a photoelectric converter 1000 including a circulator 700, a variable mirror filter 800, and an optocoupler 900.

The optical signal of the semiconductor amplifier 300 ′ is filtered to the ultra narrow bandwidth by the ultra narrow band band pass filter 500 through the isolator 400, and band-passed by the variable mirror filter 800 through the circulator 700. A round trip back to the semiconductor amplifier 300 'is performed. Hereinafter, a person skilled in the art to which the present invention pertains may easily understand FIG. 2 as a description of the configuration of FIG. 1, and thus a detailed description of FIG. 2 will be omitted.

5 is a detailed view of a phase shift optical fiber grating as an example of an ultra narrow band bandpass filter according to the first and third embodiments of the present invention.

Referring to FIG. 5, the phase shift fiber grating has a regular refractive index distribution inside the fiber core and is used as a reflective or transmissive filter. In the first and third embodiments of the present invention, two phase shift periods are provided inside the grating, and thus, the optical element is used as an optical device having ultra narrow band bandpass filter characteristics.

6 is a diagram illustrating a transmission spectrum of an ultra narrow band bandpass filter and a filter for a variable mirror according to the first to fourth embodiments of the present invention.

Referring to FIG. 6, the thin solid line is a transmission spectrum for an ultra narrow band bandpass filter and shows a transmission spectrum for a phase shift fiber grating having two phase shift intervals, and a transmission bandwidth of 0.22 pm corresponds to about 27.47 MHz. Has a frequency. The number of narrowband transmission wavelengths depends on the number of phase shift sections, and can be represented by the number of narrowband transmission wavelengths = n (n = number of phase shift sections).

Further, in FIG. 6, the thick lines ①, ②, and ③ are transmission spectra for the variable mirror filter, and thus the number and positions of the resonant wavelengths may be changed by changing the resonant wavelength position of the variable mirror filter. In detail, when the solid black line (①), one resonance wavelength (1549.545 nm) can be obtained, and when the black dotted line (②), two resonance wavelengths (1549.545 nm and 1549.575 nm) can be obtained. (In this case, a single longitudinal mode frequency is determined by the beat of two signals.) In the case of a solid gray line ③, one resonance wavelength (1549.575 nm) can be obtained. Here, in the case of black dotted line (②),

FIG. 7 is a view illustrating an electrical signal outputted by an optical fiber or a semiconductor laser light source transmitted to a photoelectric converter according to the first to fourth embodiments of the present invention.

Referring to FIG. 7, an optical fiber or a semiconductor laser light source obtained through the first to fourth embodiments of the present invention is transmitted to a photoelectric converter to represent an output converted into an electrical signal, and has a single longitudinal mode frequency. It can be seen that. Therefore, it is possible to implement a microwave signal generator based on an optical fiber or a semiconductor laser light source having a single longitudinal frequency spacing by using an ultra narrow band bandpass filter, and the resonance wavelength is freely adjusted, thereby making it suitable for optical communication and radio frequency (RF) communication. It is useful.

The present invention can generate a microwave signal by implementing an optical fiber or semiconductor laser light source that can operate in a single longitudinal mode frequency at a single wavelength or multiple wavelengths.

In addition, the use of ultra narrowband bandpass filter facilitates the shift of the output wavelength, no loss for high output, and there is no restriction on the lasing wavelength, so it can be widely used for optical communication and RF communication.

Claims (18)

A pump laser diode for generating a signal having a predetermined wavelength; A wavelength division optocoupler connected to the pump laser diode to split or couple the signal to a resonator; A gain medium activated by the signal to produce a high wavelength amplified optical signal; An ultra narrow band bandpass filter for filtering the optical signal passing through the gain medium to an ultra narrow bandwidth; A circulator formed between the gain medium and the ultra narrow band bandpass filter to rotate the optical signal and remove a reflected signal from the ultra narrow band band pass filter; A variable mirror filter formed between the gain medium and the wavelength division optical coupler to generate an optical fiber laser light source by filtering an optical signal having an ultra narrow bandwidth at a predetermined wavelength band; And And a photoelectric converter for converting the optical fiber laser light source into an electrical signal. The method of claim 1, And a polarization controller formed between the gain medium and the variable mirror filter to stabilize the polarization state of the optical signal. The method according to claim 1 or 2, The gain medium is, Microwave signal generator using an optical fiber laser light source, characterized in that any one selected from erbium (Er) or ytterbium (Yb) addition fiber, silica-based general single-mode fiber, nonlinear fiber, photonic crystal fiber and bismuth fiber . The method of claim 3, wherein The ultra narrow band bandpass filter, A microwave signal generator using a fiber laser light source, characterized in that any one selected from a phase shift fiber grating, a micro electro mechanical system (MEMS) device, a Fabry-perot filter, and a sagnac loop filter. The method of claim 4, wherein The variable mirror filter, A microwave signal generator using an optical fiber laser light source, characterized in that any one selected from among the optical fiber grating, the optical fiber grating and bulk mirrors. A semiconductor amplifier for amplifying a predetermined signal; An ultra narrow band bandpass filter for filtering the signal amplified by the semiconductor amplifier to an ultra narrow bandwidth; A circulator formed between the semiconductor amplifier and the ultra narrow band bandpass filter to rotate a signal having the ultra narrow bandwidth and remove a reflected signal from the ultra narrow band band pass filter; A variable mirror filter for generating a semiconductor laser light source by filtering a signal having an ultra narrow bandwidth amplified by the semiconductor amplifier through the circulator in a predetermined wavelength band; And And a photoelectric converter for converting the semiconductor laser light source into an electrical signal. The method of claim 6, And a polarization regulator formed between the semiconductor amplifier and the variable mirror filter to stabilize the polarization state of the optical signal. The method according to claim 6 or 7, The ultra narrow band bandpass filter, A microwave signal generator using a semiconductor laser light source, characterized in that any one of a phase shift optical fiber grating, MEMS (Micro Electro Mechanical System) device, Fabry-perot filter and Sagnac loop filter. The method of claim 8, The variable mirror filter, A microwave signal generator using a semiconductor laser light source, characterized in that any one selected from the optical fiber grating, the optical fiber grating and bulk mirror. A pump laser diode for generating a signal having a predetermined wavelength; A wavelength division optocoupler connected to the pump laser diode to divide or combine the signal and input the signal to a resonator; A gain medium activated by the signal to produce a high wavelength amplified optical signal; An ultra narrow band bandpass filter for filtering the optical signal passing through the gain medium to an ultra narrow bandwidth; A circulator having three ports, the first port being connected to the ultra narrow band bandpass filter to transmit an optical signal having the ultra narrow bandwidth; A variable mirror filter connected to a second port of the circulator to generate an optical fiber laser light source by filtering an optical signal having an ultra narrow bandwidth transmitted to the second port in a predetermined wavelength band; An optical coupler connected between the wavelength division optical coupler and the third port of the circulator and outputting the optical fiber laser light source by dividing the optical fiber laser light at a predetermined ratio; And And a photoelectric converter converting the optical fiber laser light source output from the optical coupler into an electrical signal and outputting the electrical signal. The method of claim 10, An isolator formed between the gain medium and the ultra narrow band band pass filter to remove a signal reflected from the ultra narrow band band pass filter; And And a polarization controller formed between the ultra narrow band bandpass filter and the circulator to stabilize the polarization state of the optical signal. The method of claim 10 or 11, The gain medium is, Microwave signal generator using an optical fiber laser light source, characterized in that any one selected from erbium (Er) or ytterbium (Yb) addition fiber, silica-based general single-mode fiber, nonlinear fiber, photonic crystal fiber and bismuth fiber . The method of claim 12, The ultra narrow band bandpass filter, A microwave signal generator using a fiber laser light source, characterized in that any one selected from a phase shift fiber grating, a micro electro mechanical system (MEMS) device, a Fabry-perot filter, and a sagnac loop filter. The method of claim 13, The variable mirror filter, A microwave signal generator using an optical fiber laser light source, characterized in that any one selected from among the optical fiber grating, the optical fiber grating and bulk mirrors. A semiconductor amplifier for amplifying a predetermined signal; An ultra narrow band bandpass filter for filtering the signal amplified by the semiconductor amplifier to an ultra narrow bandwidth; A circulator having three ports, the first port being connected to the ultra narrowband bandpass filter to transmit a signal having the ultra narrow bandwidth; A variable mirror filter connected to a second port of the circulator to filter an optical signal having an ultra narrow bandwidth transmitted to the second port in a predetermined wavelength band to generate a semiconductor laser light source; An optical coupler connected between the semiconductor amplifier and a third port of the circulator and outputting the semiconductor laser light source by dividing the semiconductor laser light source by a predetermined ratio; And And a photoelectric converter converting the optical fiber laser light source output from the optical coupler into an electrical signal and outputting the electrical signal. The method of claim 15, An isolator formed between the semiconductor amplifier and the ultra narrow band band pass filter to remove a signal reflected from the ultra narrow band band pass filter; And And a polarization controller formed between the ultra narrow band bandpass filter and the circulator to stabilize the polarization state of the optical signal. The method according to claim 15 or 16, The ultra narrow band bandpass filter, A microwave signal generator using a semiconductor laser light source, characterized in that any one of a phase shift optical fiber grating, MEMS (Micro Electro Mechanical System) device, Fabry-perot filter and Sagnac loop filter. The method of claim 17, The variable mirror filter, A microwave signal generator using a semiconductor laser light source, characterized in that any one selected from the optical fiber grating, the optical fiber grating and bulk mirror.

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