**4.2.2 Splicing IPHT 252b5 to SMF (Corning SMF-28)**

This PCF was difficult to splice due to small diameter. Fusion procedure included melting of fiber tips into ball lenses before fusion (Wang et a., 2008). Results depended on accurate fiber movement ("feed") before fusion: too small increased necking (Figures 29-30) and loss. Fiber was 16.08 m long, with attenuation and loss at 1558 nm of 58.3 dB/km and 0.94 dB, respectively. The SMF was Corning SMF-28. Gap during alignment was 10 µm, fibre overlap 10 µm and axial offset 200 µm towards SMF. Splicing machine settings were as follows:


Being similar to SMF, this fibre was spliced in the same way, using the following fusion program (pre-fusion, fusion, annealing - Figure 4): 9 mA – 3 s / 17 mA – 0.5 s / 9 mA – 3 s. PCF length, attenuation and loss at 1558 nm were 12.4 m, 61.5 dB/km and 0.76 dB respectively. The SMF fibre was Corning SMF-28 (Corning, 2008). Splice loss (Table 3) was acceptable despite destruction of photonic structure over 300 µm (Figures 24 and 25), due to guiding of light by doped core. This case was easy, as no special techniques were required besides reduction of fusion power and duration in comparison to SMF splicing. Lower loss

Conditions Sample loss (dB) Splice loss (dB)

Loss with finished splice No. 1 3.19 (reference) Fibres cleaved and aligned 4.79 2.37 Fibres spliced 3.77 1.25

Table 3. Loss of IPHT 282b4 sample measured during making of splice No. 2 (1558 nm).

This PCF was difficult to splice due to small diameter. Fusion procedure included melting of fiber tips into ball lenses before fusion (Wang et a., 2008). Results depended on accurate fiber movement ("feed") before fusion: too small increased necking (Figures 29-30) and loss. Fiber was 16.08 m long, with attenuation and loss at 1558 nm of 58.3 dB/km and 0.94 dB, respectively. The SMF was Corning SMF-28. Gap during alignment was 10 µm, fibre overlap 10 µm and axial offset 200 µm towards SMF. Splicing machine settings were as follows: - Splicing (pre-fusion, fusion, annealing): 9 mA – 3 s / 18 mA – 0.5 s / 8.4 mA – 3 s.

**4.2.2 Splicing IPHT 252b5 to SMF (Corning SMF-28)** 


was achievable with shorter fusion time, but at expense of reduced splice strength.

Fig. 24. SMF (left) and PCF (right) cleaved and positioned before fusion.

**4.2.1 Splicing IPHT 282b4 to SMF** 

Fig. 25. Fibres fused.

After measuring loss with butt coupling (Figure 26), fibres were melted to form ball lenses (Figures 26-28). Melting of SMF tip was repeated to obtain the required shape. After fusion (Figure 29), the splice was repeatedly heated at the same settings to reduce loss, but without further movement (Figures 29-30). Light transmission was monitored and work terminated after splice loss stopped to significantly decrease any further – see data in Table 4.

Fig. 26. Left: PCF (left) and SMF (right) aligned. Electrode tip is visible as dark triangle at the bottom of picture. Right: SMF tip melted – Phase 1.

Fig. 27. Left: SMF tip melted – Phase 2. Right: PCF positioned for melting.

Fig. 28. Left: PCF tip melted. Right: fibres aligned for fusion with axial offset.

Fig. 29. Left: fibres fused. Right: splice after additional heating No. 1.

Arc Fusion Splicing of Photonic Crystal Fibres 199

Bang, O. (2010). PCFs, mPOFs and THz fibers. *Proc. 2nd Workshop on Specialty Optical Fibers* 

Borzycki, K., Kobelke, J., Schuster K. & Wójcik J. (2010). Arc fusion splicing of photonic

Borzycki, K., Kobelke, J., Mergo, P. & Schuster K. (2011). Challenges in characterization of

Borzycki, K., Kobelke, J., Mergo, P. & Schuster K. (2011). Characterization of photonic crystal

Bourliaguet, B., Paré, C., Émond, F., Croteau, A., Proulx, A. & Vallée, R. (2003).

Corning Inc. (2008). Corning SMF-28e Optical Fiber Product Information. PI1344 (09/2008) Edvold, B. & Gruner-Nielsen, L. (1996). New technique for reducing the splice loss to

*IEC 60793-2-50 Ed. 3.0:* Optical fibres - Part 2-50: Product specifications – Sectional specification for class B single-mode fibres, ISBN 2-8318-9824-2 (05/2008) *ITU-T Recommendation G.652*: Characteristics of a single-mode optical fibre and cable (11/2009). Available from http://www.itu.int/rec/T-REC-G.652-200911-I *ITU-T Recommendation G.657*: Characteristics of a bending-loss insensitive single-mode

Law, S.H., Harvey, J.D., Kruhlak, R.J, Song, M., Wu, E., Barton, G.W., van Eijkelenborg, M.A.

Matthewson, M.J., Kurkjian, C.R. & Hamblin, J.R. (1997). Acid stripping of fused silica

Nakajima, K., Hogari, K., Zhou, J., Tajima, K. & Sankawa I. (2003). "Hole-Assisted Fiber

OFS (2008). Fitel S183PMII - A New Standard in the Field for High-End Fusion Splicing

Schott North America, Inc. (2007). Schott Technical Glasses: Physical and technical

http://www.us.schott.com/english/download/technical\_glass\_guide\_us.pdf

*Communications*, ISSN 00304018, Vol. 258, Issue 2, pp. 193–202

Optoelectronics 2011, Prague, Czech Republic, April 18-21, 2011.

*and their Applications (WSOF 2010)*, ISBN: 978-0-8194-8360-7, Oaxaca City, Mexico,

crystal fibers to standard single mode fibers. *Proc. SPIE 7714-38*, ISBN 9780819481870, SPIE Photonics Europe 2010, Brussels, Belgium, April 12-16, 2010 Borzycki, K., Kobelke, J., Schuster K. & Wójcik J. (2010). Optical, thermal and mechanical

characterization of photonic crystal fibers: results and comparisons. *Proc. SPIE 7714-31*, ISBN 978-0-81948-1870, SPIE Photonics Europe 2010, Brussels, Belgium,

photonic crystal fibers. *Proc. SPIE 8073B-107*, ISBN 978-0-81948-663-9, SPIE Optics +

fibres with OTDR. *Proc. ICTON 2011*, ISBN 978-1-4577-0881-7, paper We.B4.5,

Microstructured fiber splicing. *Optics Express*, eISSN: 1094-4087, Vol. 11, No. 25,

dispersion compensating fiber. *Proceedings of ECOC-1996*, Vol. 2, pp. 245-248, ISBN

optical fibre and cable for the access network (11/2009). Available from

& Large, M.C.J. (2006). Cleaving of microstructured polymer optical fibres. *Optics* 

optical fibers without strength degradation. *Journal of Lightwave Technology*, ISSN

Design for Small Bending and Splice Losses", *IEEE Photonics Technol. Lett*., ISSN

**7. References** 

October 13-15, 2010. Available from

Stockholm, Sweden, June 27-29, 2011

82-423-0418-1, Oslo, Norway, September 15-19, 1996

http://www.itu.int/rec/T-REC-G.657-200911-I

0733-8724, Vol. 15, Issue 3, pp. 490-497

1041-1135, Vol. 15, No. 12, pp. 1737-1739

Applications (FITEL-S183-PMII-1108)

properties (11/2007). Available from:

April 12-16, 2010

pp. 3412-3417

http://www.cio.mx/WSOF2010/archivos/Ole%20Bang.pdf

Fig. 30. Splice after additional heating No. 2 (left) and No. 3 (right).


Table 4. Loss of IPHT 252b5 sample measured during making of splice No. 2 (1558 nm).

In contrast to work presented in the preceding section, fusion splicing of small-core, thin PCF to SMF was complicated and time-consuming. However, attempts to fuse the same fibres without pre-forming resulted in very high splice loss (15.5 dB for 2 PCF-SMF splices) and frequent entrapment of small gas bubble in the centre of splice.
