Optical Devices for Communication Anritsu AF3B310DM10L

• A pump-LD (Laser Diode) is an excitation light source for a fiber amplifier used in optical communication networks.

  Types of pump-LDs include an FP-LD (Fabry-Perot Laser Diode) and FBG-LD, which connects fiber with FBG (Fiber Bragg Grating) formed on the FP-LD and provides high wavelength stability and narrow linewidth by selecting the wavelength. Spectral examples of each are indicated below.

• FP-LDs are mainly used for EDFAs (Erbium Doped Fiber Amplifiers), and output light matching the excitation wavelength of the EDFA, particularly the 1.48 um band wavelength with good excitation efficiency.

  FBG-LDs are mainly used for FRAs (Fiber Raman Amplifiers), and enable the center wavelength to be determined according to the required wavelength specifications of the FRA.

  Anritsu provides both 1.48 um LD modules suitable for EDFAs and 1.4 um FBG-LD modules suitable for FRAs.

  1.48 um LD modules provide a maximum optical output of 650 mW and a center wavelength of 1,475±15 nm, according to the required specifications of the EDFA.

  1.4 um FBG-LD modules use a PM (Polarization Maintaining) fiber with FBG (Fiber Bragg Grating) to select the wavelength, and the center wavelength can be determined according to the required specifications of the FRA. An optical output can be provided with 300 to 500 mW.

  We can also provide 1.3 um band FBG-LD modules which can be used for higher order FRA.

  Anritsu LD modules comply with Telcordia GR-468-CORE for extremely high reliability, as well as the RoHS directive. The module has an industry-standard 14-pin butterfly shape and includes a TEC (Thermo-Electric Cooler) for temperature control and PD for optical output monitor.

Features

1.48 um LD module

• Optical output: 120 to 650 mW (in 10 mW increments)
• Wavelength range: 1,475±15 nm
• Fiber: Single Mode Fiber (SMF) or Polarization Maintaining Fiber (PMF)
• Optical connector: Supports various optical connectors
• 14-pin butterfly package
• Includes optical isolator, monitor photo diode, and cooler

1.4 um FBG LD module

• Optical output and wavelength range: 410 to 500 mW/1,420 to 1,485 nm, 500 to 650 mW/1,420 to 1,470 nm
• Fiber: Polarization maintaining fiber (0.25 mm, UV coated)
• Optical connector: Supports various optical connectors
• 14-pin butterfly package
• Internal monitor PD and TEC

Applications

Optical Fiber Amplifiers (EDFA/FRA)

• Optical fiber amplification technology enables optical signal to be amplified without the need to convert it into electricity at a relay station, in order to compensate for transmission loss in optical fibers. The main types of optical fiber amplifiers are EDFA and FRA.
• EDFA uses an optical fiber core doped with the rare earth element erbium (Er, atomic number 68) as the gain medium to amplify optical signal in the 1.55 um band via optical excitation. This EDFA that was invented in the late 1990s enables batch amplification of WDM (Wavelength Division Multiplexing) and is an important element of long hole networks such as undersea optical cables and high-capacity communication systems such as access networks.
• An excitation light source for EDFA uses a 0.98 um band or 1.48 um band wavelength. Excitation light in the 0.98 um band has low quantum-conversion efficiency and a low noise figure (NF). On the other hand, excitation light in the 1.48 um band has high quantum-conversion efficiency.
• Anritsu has been providing 1.48 um LD modules as excitation light sources since EDFAs started to be used as optical amplifiers for communication.
• An FRA differs from an EDFA in that it is an optical amplifier that uses the optical fiber in the transmission route itself as the gain medium. It utilizes the nonlinear optical effect in the optical fiber called Stimulated Raman Scattering to have a gain band in the approximately 100 nm long wavelength region of the excitation light for optical signal in the 1.55 um band. Therefore, it can change the excitation light wavelength to amplify a signal light in a specific wavelength region.

Optical Fiber

• In order to obtain a more accurate excitation light wavelength, an FBG-LD is used as the excitation light source for FRA. This FBG-LD contains fiber (FBG) with a diffraction grating inside the output fiber of the LD module. This FBG enables LD optical output with high wavelength stability and wavelength selectivity. Anritsu provides FBG modules for a wide range of wavelength in the 1.4 um band.