Development of cleanliness specification for lens-based...

iNEMI Confidential

for member organization use only

Development of cleanliness

specification for lens-based

TOSA/ROSA

iNEMI F2F

OFC/NFOEC 2012

Mar 5, 2012

1 iNEMI Confidential


Project Contributors

•Glenn Victor

•Doug Wilson & Tom Mictheltree

•Tatiana Berdinskikh

•Mark Marino

•Toshiaki Satake

•Ed Stuart

•David Lach



Presentation Outline

•Background

•Project Challenges

•Different technologies of TOSA/ROSA

•Synthetic Defects Experiments

•Initial data on impact of contamination on optical performance of lens-based SFPs

•Next steps



Introduction

• No industry specification for lens-based TOSA/ROSA

• Sumitomo collected data on OC-48 SFPs in 2005-2007 • iNEMI team combined modeling and experimental data (2008-

2009) to study contamination effects on lens-based devices

– 10G SFP+ Sumitomo transceiver was used a test vehicle for the project

– Paper has been published at OFC/NFOEC09 conference ( San Diego, CA, Mar, 09)

• Further research is required for development of cleanliness specification of lens-based receptacles


for member organization use only 4

Pluggable Optics – Common MSA Package Types

SNAP12 MSA

Parallel Optic Device



Challenges

•Multiple designs of lens-based transceivers in use

–The collaboration efforts between different module

manufactures, CMs and OEMs are required

•Difficult contamination techniques

– Manual process with low repeatability and reproducibility

•Cleaning process of lens-based receptacles is challenging

due to limited access to lens surface



ROSA/TOSA Technologies

• Many different internal structures within OSA devices have been

discovered

• The differences, amongst multiple suppliers, create a huge

challenge for defining inspection and cleaning requirements

• Several of these designs are shown in next slides



Integral Lens Sample

•This sample separates

the LC cavity and end-

face from the integral lens

surface.



Multiple lens Sample

•This sample utilizes a

“Contact Type” lens that

makes physical contact

with the LC end-face.

•The lens floats, and is

not hermetically sealed

within the OSA structure.

•Cleaning of the contact

flat lens is practical.



Spherical Lens Sample

•This sample utilizes a full

spherical lens.

•Adjacent volume is open,

creating an “air” interface

for the installed LC

connector.

•Distance from the LC

aperture, to the leading

surface of the “Ball Lens”

is ~ 2.28mm



Semi-spherical Lens Sample

•This sample utilizes a

semi-spherical lens,

along with an “air”

interface for an LC

connector.

•A lens is also present on

the plate glass surface of

the TO-Canister.

•The distance from the

LC aperture to the

leading lens surface is ~



Semi-spherical Lens Close to Aperture Sample

•This sample represents

a structure where the

semi-spherical lens

surface is near the LC

aperture.

•Open volume surrounds

the lens

•The distance from the

LC aperture to the

leading lens surface is ~

1.31mm.



Sophisticated Structures Sample

•Sophisticated structures,

and optical components,

other than lenses, may

reside.

•This structure includes

what is believed to be an

isolator, within the optical

path.

•As the isolator emerging

surface is angled,

cleaning and inspection



Optical Subassembly Construction

•TO can assembly into OSA housing

•Photodiode / LED / laser position inside TO can

•Fiber into OSA housing

•Theoretical path of light



Transceiver De-construction for Testing

SFP transceiver with lens-based transmitter and receiver



Transceiver de-construction for testing

• Cutaways made in metal housing to expose lens without affecting the optical

transmission

• Facilitates easy contamination and re-cleaning.

• Maybe re-assembled back into the module for performance testing.



Receiver signal loss with contamination, dB

Images at (200x)

-1.04

-1.80

-1.54

Conductive Foam

-4.30

-6.40

-2.57

Toner Clean Lens



DOE for Controlled Blockage

•Measure output power with no interference

•Use microscope to measure active area of lens

•Capture image of synthetic defect at each pre-defined

measurement location (X and Y) with XMTR ON and OFF

•Reconnect to power meter, move to each XY location, and

measure output power

•Plot output power in 2D intensity graph for analysis

•Repeat for each defect type

Using Synthetic Defects



Synthetic Defect Patterns

• Patterns block the XMTR output to varying degrees based on the defect pattern and its location

within the part

• Several defect types have been designed

– opaque circles of diameters (50-600 um)

– opaque circles with holes, “donuts” (50-450 um holes)

– Lines >500 um long with widths of 50-600 um

– Clusters of randomly distributed opaque circles with varying density and total occluded area



Photos of Mylar Film Synthetic Defects

•Opaque Circles

•Donuts

50 m 200 m 450 m

50 m 200 m 450 m



Mylar Strip with “Donuts” in TOSA Device

• Slotted TOSA device provided

means to insert synthetic defect

strips

• Initial sample of Mylar film with

donut shapes

• Final version will have supports to

enable repeatable motion of the

strip within the slot

• Microscope can image the defects

with or without the transmitter

enabled

• Output power can be measured by

cabling to a power meter



Initial Images of Synthetic Defects

• Transmitter was ON, which is source of circle of light.

• Top row is 265 um defect, lower row defect is ~540 um in dia

• Illuminated area is ~600 um in diameter, as viewed through the aperture in device.

• Size of defects and transmitter circle are both increased by same proportion, most likely correct for separation distance from

device.

• Roughness at edge of circle is defocusing of the sharp edge of the aperture



TOSA Focus Journey

• Movie not included in this version



TOSA Synthetic Defects

• Movie not included in this version



Preliminary Power Readings

• Quick readings were made of output power as a synthetic defect

strip was randomly move around

• Observed about 20-25 dB decrease in output power as large circle

was moved into the main path

• While not a controlled experiment, it was encouraging to see the

defect quench the output as expected

• Next step is carefully controlled motion with quantitative measure

of occlusion to match with output power measurements



Next Steps

• Collect additional images and associated optical performance data

on contaminated samples

• Conduct controlled synthetic defect experiment to quantify

relationship between occluded area and optical performance

• Optical performance metrics include output power loss and

receiver loss

iNEMI Confidential


www.inemi.org Email contacts:

Bill Bader [email protected]

Bob Pfahl [email protected]

Development of cleanliness specification for lens-based...

Documents

Transcript of Development of cleanliness specification for lens-based...