- Maintain Polarization State of Input
- Panda or Bow-Tie Style Fiber
- Stock and Custom Patch Cords Also Available
Thorlabs offers both Panda and bow-tie style Single Mode Polarization-Maintaining (PM) fiber. The two styles are named based on the stress rods used. Stress rods run parallel to the fiber's core. Panda stress rods are cylindrical, while bow-tie uses trapezoidal prism stress rods. For the average user, these two styles are interchangeable. Panda style fibers have historically been used in telecom applications, as it is easier to maintain uniformity in their cylindrical stress rods over very long lengths when manufacturing.
Although bow-tie fibers are not traditionally used in telecom applications, we do offer specialized bow-tie fibers. The HB980T fiber has been optimized for telecom use with polarization multiplexing of EDFA pump lasers. Additionally, the HB1250T and HB1500T are well suited for both laser and integrated optic chip pigtailing.
Applications such as Fiber Optic Gyroscopes (FOG) can benefit from the HB800G bow-tie fiber. FOGs require optimal performance over a wide temperature range, short beat lengths, and high birefringence. Conventional PM fibers use a polymer coating, which become less flexible at lower temperatures. This causes undesired stress in the fiber and degrades its performance at low temperatures. Our HB800G integrates a dual-layer acrylic coating that increases the low temperature performance (Temperature Performance Plot).
Polarization-Maintaining Fiber, Panda Style
|PM-S350-HP||350 - 460 nm||2.3 μm @ 350 nm||0.12||≤340 nm||N/A||1.5 mm @ 350 nm|| Ø125 ± 2 µm||Ø245 ± 15 µm||13 mm||T06S13|
|PM-S405-XP||400 - 680 nm||3.6 ± 0.5 μm @ 405 nm|
5.0 ± 0.5 μm @ 630 nm
|380 ± 20 nm||≤30.0 dB/km @ 488 nm|
≤30.0 dB/km @ 630 nm
|2.0 mm @ 405 nm|
|PM460-HP||460 - 700 nm||3.3 ± 0.5 µm @ 515 nm||420 ± 30 nm||<100 dB/km @ 488 nm||1.3 mm @ 460 nm|
|PM-S630-HP||630 - 780 nm||4.2 ± 0.5 µm @ 630 nm||580 ± 40 nm||<12 dB/km @ 630 nm||4.7 mm @ 630 nm|
|PM630-HP||620 - 850 nm||4.5 ± 0.5 μm @ 630 nm||570 ± 50 nm||<15 dB/km @ 630 nm||1.8 mm @ 630 nm|
|PM780-HP||770 - 1100 nm||5.3 ± 1.0 µm @ 850 nm||710 ± 60 nm||<4 dB/km @ 850 nm||2.4 mm @ 850 nm|
|PM980-XP||970 - 1550 nm||6.6 ± 0.7 µm @ 980 nm||920 ± 50 nm||≤2.5 dB/km @ 980 nm||≤2.7 mm @ 980 nm|
|PM1300-HP||1270 - 1625 nm||9.5 ± 1.0 µm @ 1300 nm||0.13||1200 ± 70 nm||<1.0 dB/km @ 1300 nm||≤4.0 mm @ 1300 nm|
|PM14XX-HP||1390 - 1625 nm||9.8 ± 0.8 µm @ 1450 nm||1320 ± 60 nm||<1.0 dB/km @ 1450 nm||≤4.7 mm @ 1450 nm|
|PM1550-XP||1440 - 1625 nm||9.9 ± 0.5 µm @ 1550 nm||0.125||1370 ± 70 nm||<1.0 dB/km @ 1550 nm||≤5.0 mm @ 1550 nm|
|PM2000||1850 - 2200 nm||8.0 µm @ 1950 nm||0.20||1720 ± 80 nm||≤11.5 dB/km @ 1950 nm|
≤22.5 dB/km @ 2000 nm
|5.2 mm @ 1950 nm|
Polarization-Maintaining Fiber, Bow-Tie Style
|Item #||Design Wavelength(s)a||MFDb||NA||Cutoff||Attenuation||Beat Lengthc||Cladding Diameter||Coating Diameter||Strip Tool|
|HB800G||830 nm||4.2 µm||0.14 - 0.18||680 - 780 nm||<5 dB/km||<1.5 mm||Ø80 ± 1 µm||170 µm ± 5%||N/A|
|HB980T||980 nm||6.0 µm||0.13 - 0.15||870 - 970 nm||<3 dB/km||<2 mm||Ø125 ± 1 µm||245 µm ± 5%||T06S13|
|HB1250T||1310 nm||9.0 µm||0.11 - 0.13||1100 - 1290 nm||<2 dB/km||<2 mm||Ø125 ± 1 µm||400 ± 5%||N/A|
|HB1500T||1550 nm||10.5 µm||0.11 - 0.13||1290 - 1540 nm||<2 dB/km||<2 mm||Ø125 ± 1 µm||400 ± 5%||N/A|
Definition of the Mode Field Diameter
The mode field diameter (MFD) is one measure of the beam width of light propagating in a single mode fiber. It is a function of wavelength, core radius, and the refractive indices of the core and cladding. While much of the light in an optical fiber is trapped within the fiber core, a small fraction propagates in the cladding. For a Gaussian power distribution, the MFD is the diameter where the optical power is reduced to 1/e2 from its peak level.
Measurement of MFD
The measurement of MFD is accomplished by the Variable Aperture Method in the Far Field (VAMFF). An aperture is placed in the far field of the fiber output, and the intensity is measured. As successively smaller apertures are placed in the beam, the intensity levels are measured for each aperture; the data can then be plotted as power vs. the sine of the aperture half-angle (or the numerical aperture).
The MFD is then determined using Petermann's second definition, which is a mathematical model that does not assume a specific shape of power distribution. The MFD in the near field can be determined from this far-field measurement using the Hankel Transform.