Category

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 »Distributed Bragg Reflector(DBR) Fiber Laser

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 »Narrow Linewidth Fiber Laser

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 »High-peak-power Nanosecond Fiber Laser

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 »CW MOPA Fiber Laser

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 »High Power Polarization Maintaining CW Fiber Laser

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 »High Power Pulsed Polarization Maintaining Fiber Laser

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 »SUMMARY

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Practical Application of High Power Fiber Components Manufactured by Bonacom in Continually Developing Single-Frequency Fiber Laser

 

    »Since the first demonstration by Snitzer in 1964, fiber lasers have experienced extensive research and development over the past six decades, especially over the past decade, with the development of fiber material and drawing technology, fiber component fabrication, and high-brightness pumping diodes, the performance of fiber lasers has been improved in various aspects. single-frequency fiber lasers,which means lasers running with single-longitudinal-mode, have attracted intense attention and have been broadly researched recently.

   The single-frequency fiber lasers have implement different configurations to demonstrate single-longitudinal-mode operation. In general, they can be summarized as distributed feedback(DFB) fiber lasers, distributed Bragg Reflector(DBR) fiber lasers, and ring cavity fiber lasers embedded with narrow-bandwidth filters.

   A DFB fiber laser is composed of a piece of fiber Bragg grating(FBG) written directly in the active fiber, which introduces a phase change in the middle of the grating area. The resulting structure functions as an ultranarrow spectral filter to achieve single-mode oscillation.

   The DBR single-frequency fiber laser is another typical linear cavity design with the structure shown in Fig.1. The laser cavity combines a pair of Bonacom’s narrowband FBGs(HR FBG, OC FBG) with a short piece of rare-earth-doped fiber, two pieces of  Bonacom’s FWDM(980/1064nm, BNFWDM-9806, Bonacom Technology, Shenzhen,China). DBR fiber lasers are preferred in the development of single-frequency fiber lasers because of their compactness and robustness.

 

 

   »In addition to high output power, operation with low noise is also required. To date, many techniques have been developed to suppress the intensity and frequency noise of single-frequency fiber lasers. The low-frequency noise caused by the pump noise and external disturbances, can be eliminated with an optoelectronics feedback circuit.

 

With the demand increase of some practical applications,such as high-precision metrology, gravitational wave detection, and coherent LIDAR, fiber laser operating with narrow linewidths are urgently required. Single-frequency fiber lasers have marvelous performance in terms of laser linewidth, which results in ultralong coherence length.To further compress the linewidth of a short-linear-cavity fiber laser, a virtual-folded-ring configuration, which combines the advantages of ring lasers and short-linear-cavity lasers, was proposed by Moetal. As shown in Fig.2, a piece of polarization-maintaining fiber (PM-F) was used inside the cavity,acting as an all-fiber quarter-wave plate to achieve polarization retardation. Bonacom’s polarization maintaining isolator(PMIS,BNPMIS-06-S), polarization maintaining FWDM(PMFWDM,BNPMWDM-U-0698), PM FBGs are first choice for such application.

 

 

   »In order to test the linewidth control improvement in the high-power amplifier, here built a two-stage LMA fiber amplifier, as shown in Figure 3.

 

   

Bonacom Technology’s high power fiber components with 1064nm central wavelength below are widely used in such fiber amplifier system:(2+1)x1 pump signal combiner(BNPC-4-06-10125),cladding power stripper(CLS,BNCLS-06-10125-30),high power optical circulator(CIR,BNHPCIR-06-A),(6+1)x1 pump signal combiner(BNPC-8-30250),cladding power stripper(CLS,BNCLS-06-30250-100), high power collimator(CO,BNHPCO-06), high power fiber in-line mirror(Mirror, BNHPM-06).

 

    »For CW higher laser power achievement, single-frequency fiber sources are generally configured as a high-gain fiber master oscillation power amplifier (MOPA), which is seeded by a low-power, single-frequency oscillator and then followed by a series of amplifier stages to realize power amplification, as shown in Fig. 4 & 5.

 A. High-Power CW Single-Frequency Fiber Amplifiers 

 

     »B. High-Power Polarization Maintaining CW Single-Frequency Fiber Amplifiers.

 

 

Bonacom Technology’s high average power polarization maintaining(PM) fiber components with 1064nm central wavelength below are widely used in typical single-frequency polarization maintaining fiber MOPA with three-stage amplifier application:

PM FWDM(BNPMFWDM-0698-S), PM bandpass filter(BPF, BNPMBPF-2-10), PM Isolator(BNPMIS-06-S), (2+1)x1 PM pump signal combiner(BNPMPC-4-S), high power PM isolator(BNHPPMIS-06-S), mode-field adapter(MFA,BNMFA-06-2030),(6+1)x1 PM pump signal combiner(BNPMPC-8-S), cladding power stripper(CPS,BNCPS-20-S), high power collimator (BNHPCO-06-50), high power polarization beam splitter (BNHPPBS-06-S).

 

   »Some practical applications,such as coherent LIDAR, remote sensing, and nonlinear frequency conversion, require single-frequency fiber-laser pulsed operation with high energy or peak power. A high-gain MOPA laser system shown in Fig. 6 is usually needed to further scale up the power/energy of the single-frequency pulses.

 C.High-Power/Energy Pulsed Single-Frequency Fiber Amplifiers

 

Bonacom manufacture stable high peak power polarization maintaining fiber components with 1550nm central wavelength below:(2+1)x1 polarization maintaining pump signal combiner(BNPMPC-4-55-S),1550nm PM FBGs(HR FBG, OC FBG),PM isolator(PMIS,BNPMIS-55-S),(6+1)x1 polarization maintaining pump signal combiner(BNPMPC-8-55-S).

 

SUMMARY

Single-frequency fiber lasers were briefly reviewed with recent progress in this paper, including recent progress. With the development of heavily rare-earth-doped soft glass fiber, watt-level output power has been achieved for single-frequency fiber oscillators. Performance improvement on laser linewidth and noise has been continuously pushed forward with the newly developed physical mechanisms. Efforts to increase the output power/energy of single-frequency fiber amplifiers have been made with different strategies on the suppression of the SBS effect and even mode instability. One should expect substantial progress in this area with new fiber designs and system architectures. All of this would further motivate the applications of single-frequency fiber lasers in broader areas from science,defense, and industry to our daily life. 

Bonacom Technology is specialized in manufacturing high power(average power & peak power) fiber components(polarization maintaining/non-PM) for various Fiber Lasers application. The average power can up to 200Watts,the peak power can up to 100kW. These components include high power isolator, high power circulator, high power FWDM, high power polarization beam splitter, high power collimator, high power fiber-to-free space isolator, pump signal combiner, Mode-field adapter, cladding power stripper with working wavelength at 1550nm,1064nm,980nm.

 

We also offer custom optical modules and subsystems by integrating multiple broadband components such as isolator coupler FWDM PBS hybrid. These components are ideal choices for continually developing fiber laser systems. Contact Bonacom Technology to discuss your requirements.