In-Line Fiber Optic Polarizers

Passive, In-Line Fiber Polarizers
Six Center Wavelengths from 630 to 1550 nm
FC/PC or FC/APC Connectors

ILP780PM-FC

Small In-Line Package

FC/APC

FC/PC

Labeled
Output and
Input Ends

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Overview
Feedback

Common Specifications^a
Maximum Power	300 mW
Return Loss^b	≥45 dB
Package	Ø5.5 mm x 35 mm
Jacket Type	Ø900 μm Loose Furcation Tubing
Pigtail Length	0.8 m +0.075 / -0.0 m on Each Side
Connector Key Size	2.0 mm Narrow Key Aligned to Slow Axis
Operating Temperature	-5 to 70 °C
Storage Temperature	-40 to 80 °C

All Specifications Include Connectors
The actual return loss will be higher for FC/APC-terminated models than FC/PC-terminated models because the angled ferrule minimizes back reflections.

Features

Small, Durable Package (Ø5.5 mm x 35 mm)
Available Wavelengths:
- 630 ± 10 nm
- 780 ± 10 nm
- 850 ± 10 nm
- 980 ± 10 nm
- 1064 ± 30 nm
- 1310 ± 50 nm
- 1550 ± 50 nm
FC/PC or FC/APC Narrow Key (2.0 mm) Connectors
Two Fiber Types Available:
- Polarization Maintaining (PM)
- Single Mode (SM) Fiber Available for 1550 nm Polarizers

Thorlabs' in-line fiber polarizers are designed to pass linearly polarized light while blocking the orthogonal polarization from an unpolarized (or randomly polarized) light source. They can attenuate the orthogonally polarized light with a high extinction ratio of at least 23 dB, depending on the specifics of each polarizer (see the tables below). These polarizers can also be used to enhance the extinction ratio of polarized signals. For the PM versions of these devices, the output polarization and 2.0 mm narrow key of the connector are aligned to the slow axis of the fiber. For FC/APC-terminated versions, the return loss will be higher than for FC/PC-terminated versions because the angled ferrule minimizes back reflections.

In-line fiber polarizers are ideal for fiber optic networks and measurement applications, including polarization analysis, polarization monitoring and control, polarization mode dispersion (PMD) monitoring, and polarization extinction ratio (PER) improvement. They work well with polarization-maintaining fiber amplifiers, fiber lasers, and high-speed communication systems and instrumentation. We also offer PM Patch Cables, PM Pigtailed Laser Diodes, and PM Laser Sources, which are perfect for use with our fiber polarizers.

Reverse Operation
Each pigtailed end of these in-line fiber polarizers is marked as "Input" or "Output" to facilitate use. The polarizers may be used in reverse, but all specs, including insertion loss and extinction ratio, may vary from those given on this page.

Fiber Polarization Control Selection Guide
Polarization Controllers				Linear Polarizers

Manual Paddle Fiber Polarization Controllers	In-Line Manual Fiber Polarization Controller	Free-Space FiberBench	Faraday Mirrors	In-Line Fiber Polarizers	Polarizing Fiber

Posted Comments:

user (posted 2024-07-28 01:45:04.323)

Hi, I want to use the in-line polarizer for sensing. If I have a linearly polarized laser and a polarization controller, can I use the in-line polarizer (at 1550nm) as the "ANALYZER"? This means that I can change the input laser polarization to be perpendicular to the polarization of the in-line polarizer, getting 0 intenisty at the output? Also, howcan I connect PM fiber to the in-line PM fiber polarizer? Thanks!

jpolaris (posted 2024-07-30 06:05:11.0)

Thank you for contacting Thorlabs. If you were to cross-align the input polarization state with the transmission axis of the ILP1550PM-FC, you wouldn't get exactly zero throughput. We spec an extinction ratio of ≥ 26 dB (Min) / 28 dB (Typ.) for ILP1550PM-FC. That is, with a sufficiently linearly polarized source, the ratio of maximum transmission (when the polarization state is aligned with the transmission axis) to minimum transmission (cross-aligned), is 10^(28 dB/ 10) = 630. If you have some amount of transmission while the polarization axis is aligned with the transmission axis, you can expect to get 630x less transmission if you were to rotate the polarization axis by 90°. To connect a PM fiber to ILP1550PM-FC, you can use a polarization-maintaining FC/PC to FC/PC mating sleeve. The FC/PC connector on ILP1550PM-FC is a narrow-key type, so I recommend ADAFCPM2.

Magnus Linnet Madsen (posted 2024-04-22 09:36:12.567)

Hi, someone else has asked a similar question but have you measured the extinction ratio outside of the specified bandwidth for the 850?

cdolbashian (posted 2024-04-26 02:29:07.0)

Thank you for reaching out to us with this inquiry Magnus. I have contacted you directly regarding the specific wavelength you are seeking.

Amruthaa Sundararaj (posted 2023-11-06 10:48:35.717)

Please provide an SM to PM version of these inline polarizers. Most of my applications involve using a fiber polarization controller and inline polarizers to go from SM to PM to control the optical power as well as polarization.

cdolbashian (posted 2023-11-15 10:12:32.0)

Thank you for this suggestion! I have submitted this to our internal product development team so that it may be considered for a future release.

user (posted 2022-09-28 15:30:28.103)

Hi, I can see that the central wavelength tolerance for this product is +-50 nm from 1550. Do you have any measurement/data to suggest I can extend the use of this all the way, for example, to 1650 nm? How will this impact the experiment? Alternatively, do you offer something similar that operates well all the way from 1500 nm to 1700 nm? Any comments/leads/suggestions would be highly appreciated. -BR Ashik

jgreschler (posted 2022-10-19 04:17:49.0)

Thank you for reaching out to Thorlabs. The polarization extinction ratio (26 db min/ 28db typ) is only guaranteed for wavelengths within the range specified, operating outside that range will impact the effectiveness of the device.

akn akn (posted 2022-08-23 13:56:03.023)

Kindly confirm the Numerical aperture i.e. NA of the PM fiber used in ILP1550PM-APC

jgreschler (posted 2022-09-14 03:36:23.0)

Thank you for reaching out to Thorlabs. Additional specifications and data can be requested by contacting techsupport@thorlabs.com. I have reached out to you directly with further details.

Luis Herrera (posted 2022-06-29 08:00:08.05)

Good afternoon. I have a doubt about the in-line polarizer: https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5922 In which polarization is the output of the in-line polarizer ?? I mean, a PBS (polarization beam splitter) saparates light in its components :Horizontal and Vertical, thus in the case of in-line polarizer, which component is in the output, the vertical or the horizontal ?? (note that the reference is that the key of the connector are aligned to the slow axis) Thank you very much. Luis

cdolbashian (posted 2022-07-06 11:45:13.0)

Thank you for reaching out to us with this confusion. Noted on the overview page: "... the output polarization and 2.0 mm narrow key of the connector are aligned to the slow axis of the fiber."

Volkmar Schultze (posted 2020-11-19 07:28:22.177)

I'm looking for an In-Line Fiber Optic Polarizers for 894nm wavelength (and with FC/(APC connector). Can you offer this? And to which conditions?

YLohia (posted 2020-11-19 10:19:22.0)

Thank you for contacting Thorlabs. Quotes for custom items can be requested by clicking the red "Request Quote" button above or emailing your local Thorlabs Tech Support team (europe@thorlabs.com in your case). We will discuss the possibility of offering this directly.

Tong Wang (posted 2020-10-12 22:56:17.8)

想请问一下该光纤起偏器的工作原理是什么？货期大概多长时间

YLohia (posted 2020-10-13 09:40:26.0)

Thank you for contacting Thorlabs. An applications engineer from our team in China (techsupport-cn@thorlabs.com) will contact you directly.

Ali Altaher (posted 2019-04-15 03:21:30.61)

Hi How much it cost if I need you to manufacture a 640 nm wavelength of operation, and what time it take? Also, I need to know what is the kind of polarization controlling that is happening here. Thank you

YLohia (posted 2019-04-15 11:48:12.0)

Hello, thank you for contacting Thorlabs. Quotes for custom items can be requested by clicking the red "Request Quote" button above or emailing your local Thorlabs Tech Support team (techsupport.uk@thorlabs.com in your case). I will reach out to you directly to discuss the possibility of offering this.

x.a.attendu (posted 2019-03-08 08:40:48.94)

Dear Sir/Madam, I was wondering if a 1310 nm, SM pigtailed FC/APC option would be available ? Thanks in advance

llamb (posted 2019-03-13 08:23:20.0)

Thank you for contacting Thorlabs. For quote requests for custom items, you may reach out to your local Tech Support team (Europe@thorlabs.com in your case). Also, using a polarizer with single mode fiber will not maintain the output polarization, so we will reach out to you directly by email in this case to discuss your application further.

549654706 (posted 2019-01-15 17:24:38.147)

Do you have the in-line fiber polarizers whcih have the center wavelength of 2000nm ?

YLohia (posted 2019-01-15 12:43:14.0)

Hello, thank you for contacting Thorlabs. Quotes for custom items can be requested by emailing your local Thorlabs Tech Support team (techsupport-cn@thorlabs.com in your case). I will reach out to you directly to discuss the possibility of offering this.

Andrew (posted 2018-06-28 11:05:29.71)

Hi, According to Malus's Law, polarizer has to pass 0.5 or 3dB of input light. Your specification points less than 1 dB. Where is the hint? :-) Or it is necessary to add 3 dB to spec? Thanks!

YLohia (posted 2018-07-03 10:30:04.0)

Hello, thank you for contacting Thorlabs. The spec you are referring to is the insertion loss of the unit, which includes fiber-to-fiber coupling, etc.

bsslv (posted 2018-05-30 03:28:26.453)

Hi, My name is Sung, and just wanna ask about this device, ILP1550PM-FC. I already know PM means Polarization Maintaining, and what is the role of the part of 'Small in-Line package' ? AND Why this device is called likes 'polarizers' ? Is this makes some polarization? As I known by checking the spec sheet, I could not found about the information whether it makes TM or TE polarization. Is it right? Yes, That's all. Thx. Best regard,

YLohia (posted 2018-05-31 11:26:23.0)

Hi Sung, the "small in-line package" refers to the fact that the polarization module is "in-line" with the fiber and is quite small (35 mm long with a 5 mm diameter). These units can polarize light by taking in unpolarized light and only passing through one linear state (aligned to the slow axis of the fiber). TE or TM polarization only have meaning in the context of a defined reference plane. The relevant information here is that the slow axis of the fiber is aligned to the connector key, so depending on the orientation of your output fiber key, you can get a linear polarization state at any arbitrary angle.

melanie (posted 2018-01-30 15:21:48.993)

can you do these at 635 nm please as they are so very useful !

nbayconich (posted 2018-03-27 10:00:34.0)

Thank you for contacting Thorlabs. We can provide a custom in line fiber polarizer for 635nm, I will contact you directly with more information about our custom capabilities.

o.puncken (posted 2017-11-08 12:02:52.81)

Dear Sir or madam, we recently bought an in-line polarizer for 1550nm to build a linearly polarized Erbium ASE source: We pump an Er-doped non-pm fiber, to create some broad unpolarized fluorescence. We then spliced an ILP1550PM-AC to this setup and measured the PER with a combination of half waveplate and PBS, which was only 1:2. The fiber cores of the EDF and the polarizer match. An additional quarter waveplate fixes the bad PER, but in the end we need an all-fiber setup. Any ideas on this ? Best regards, Oliver Puncken Laser Zentrum Hannover e.V. Tel.: +49 511 2788 377

tfrisch (posted 2018-01-16 04:23:36.0)

Hello, thank you for contacting Thorlabs. The most common reason for a poor extinction ratio would be a significant portion of the spectrum outside the operating band of the filter (1550nm ± 50nm). I will reach out to you to discuss the source you are using and your expected output spectrum from the fiber.

user (posted 2017-01-31 17:36:56.1)

For the isolators with PM fiber patch-cords, which fiber axis is transmitted please? i.e. does it block the fast or the slow axis? Many thanks.

tcampbell (posted 2017-02-02 12:34:37.0)

Response from Tim at Thorlabs: thank you for your question. The output polarization is aligned with the slow axis of the fiber, while the fast axis is blocked. The 2.0 mm narrow key of the connector is also aligned with the slow axis of the fiber, so the orientation of the connector will indicate the direction of output polarization.

emeyersc (posted 2014-05-27 15:19:33.993)

I am interested in using the ILP1550SM to co-polarize a few different co-propagating laser fields, e.g. at 1400nm, 1550nm and 1600 nm. What happens if 1400nm light is sent through the polarizer? Does it polarize correctly but poorly, or does it transmit a different polarization than the wavelengths within spec?

myanakas (posted 2014-06-11 10:10:46.0)

Response from Mike at Thorlabs: Thank you for your feedback. It is possible to polarize the fiber at that wavelength but we cannot guarantee the extinction ratio through the fiber. Also, the fiber may propagate a second mode so the signal may not be the best. If you mandrel wrap the fiber you can possibly eliminate that second mode.

630 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP630PM-FC	630 nm	±10 nm	1.6 dB (Typ.) / ≤1.8 dB (Max)	≥22 dB (Min) / 24 dB (Typ.)	PM630-HP	FC/PC
ILP630PM-APC	630 nm	±10 nm	1.6 dB (Typ.) / ≤1.8 dB (Max)	≥22 dB (Min) / 24 dB (Typ.)	PM630-HP	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

780 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP780PM-FC	780 nm	±10 nm	1.1 dB (Typ.) / ≤1.3 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	PM780-HP	FC/PC
ILP780PM-APC	780 nm	±10 nm	1.1 dB (Typ.) / ≤1.3 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	PM780-HP	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

850 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP850PM-FC	850 nm	±10 nm	1.1 dB (Typ.) / ≤1.3 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	PM780-HP	FC/PC
ILP850PM-APC	850 nm	±10 nm	1.1 dB (Typ.) / ≤1.3 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	PM780-HP	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

980 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP980PM-FC	980 nm	±10 nm	1.0 dB (Typ.) / ≤1.2 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	Fujikura SM98-PS-U25D	FC/PC
ILP980PM-APC	980 nm	±10 nm	1.0 dB (Typ.) / ≤1.2 dB (Max)	≥23 dB (Min) / 26 dB (Typ.)	Fujikura SM98-PS-U25D	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

1064 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP1064PM-FC	1064 nm	±30 nm	0.70 dB (Typ.) / ≤0.90 dB (Max)	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM98-PS-U25D	FC/PC
ILP1064PM-APC	1064 nm	±30 nm	0.70 dB (Typ.) / ≤0.90 dB (Max)	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM98-PS-U25D	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

1310 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Extinction Ratio^b	Fiber Type	Connectors
ILP1310PM-FC	1310 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM13-PS-U25D	FC/PC
ILP1310PM-APC	1310 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM13-PS-U25D	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.

1550 nm In-Line Fiber Polarizers

Item #^a	Center Wavelength	Bandwidth	Insertion Loss^b	Polarization- Dependent Loss	Extinction Ratio^b	Fiber Type	Connectors
ILP1550PM-FC	1550 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	N/A	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM15-PS-U25D	FC/PC
ILP1550PM-APC	1550 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	N/A	≥26 dB (Min) / 28 dB (Typ.)	Fujikura SM15-PS-U25D	FC/APC
ILP1550SM-FC	1550 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	≤28 dB	N/A	SMF-28e+	FC/PC
ILP1550SM-APC	1550 nm	±50 nm	0.60 dB (Typ.) / ≤0.80 dB (Max)	≤28 dB	N/A	SMF-28e+	FC/APC

All specifications include connectors.
Specified at 23 °C and over the entire bandwidth.