OFC 2013: Finisar WaveAnalyzer Product Demonstration

See Us at OFC 2013! Optical Instrumentation Preview

OFC is upon us once again – this year taking place near “the happiest place on earth” in sunny Anaheim, home of Disneyland.

The Instrumentation Group from Finisar Australia will be showing the new WaveShaper 100S Tunable Optical Filter as well as demonstrating the new WaveShaper 2000 Polarization Processor and the advanced WaveShaper Fourier Processor software (the “Optical FPGA”) in Finisar’s booth #2405.

We’re particularly excited about our new WaveAnalyzer 1500S, a High Resolution Optical Spectrum Analyzer which is being released at the show (read press release). This is based on coherent detection and offers sub-picometer wavelength resolution across the entire C-band together with blindingly fast measurement speeds. The WaveAnalyzer 1500S is an amazing beast providing a unique combination of ultra-high resolution and high-speed spectral analysis and can acquire a full C-band scan with 20 MHz spectral resolution in only 250 msec, whilst a detailed spectral analysis of a 100 GHz window can be obtained in under 25 msec.

The WaveAnalyzer 1500S has a very small footprint (the same as our WaveShaper range) and low power consumption, together with an extremely intuitive user interface and a comprehensive API for integration into automated measurement systems. Come and have a play with it at the Finisar booth #2405.

The Sydney team are also involved in a number of panel sessions and workshops at the conference. In the WSS/ROADM area, Steve Frisken, is a speaker on the panel “Will Flexgrid Networks be Worth the Investment?” whilst Ken Falta is on the “Future of ROADM Technology: Deployment and Functionality” panel and Michael Roelens is a presenter at the workshop to discuss “What Is the Best Technology for Wavelength- and Space-division Cross Connects”. I’m speaking at the workshop “If the technology for SDM (Spatial Division Multiplexing) exists, do we want to use it?”.

Look forward to seeing you at OFC next week!

ECOC 2012: Monday Report from Simon Poole

The process by which the trade show goes from an empty hangar to the clean, professional environment that greets the attendee when it opens, never ceases to amaze me. The Finisar booth (#500) is right in front of the show entrance and has undergone its usual transformation from an ugly duckling on the Sunday before the show to the beautiful swan that it is when the show opens. As with all swans, the graceful exterior hides the frantic activities below the water and it is a credit to all the engineers who have put in huge efforts to get the demos all working come opening time.

At the Finisar booth we’ve a range of demonstrations and product releases (read our ECOC 2012 show announcements). On the WaveShaper front, we’re demonstrating a range of new capabilities as discussed in previous posts – polarization processing, power splitting, etc. as well as demonstrating the WaveSketch app for quick generation of simple filters. There is also a demonstration of the capabilities of Finisars Board Mounted Optical Engine (or BOA) which is designed for high-speed optical interconnects both between chips and between circuit boards.

The biggest demonstration, however, is a demo of a 2x1xN two-slot ROADM line card with Flexgrid(TM) capabilities. This includes a high port-count WSS together with a high speed multi-port Flexgrid Optical Channel Monitor. This isn’t immediately visible from the booth entry, but have a chat with our friendly booth staff to schedule a chance to see this excellent piece of engineering.

I managed to fit in a few talks amongst the days customer meetings and general meet and greets. Highlight of those that I saw was the review by S J Ben Yoo from UCD on his groups work on arbitrary waveform generation – a real technological tour de force with over 1200 active optical devices integrated onto a single 3″ InP wafer.

I’ll be back tomorrow with more reports from the technical sessions!

MORE Applications for LCoS Technology and Introducing WaveShaper 2000S

This week’s blog post is provided by featured author, Dr. Simon Poole.

Last time I blogged about an advanced feature of an LCoS-based WSS, namely the ability to controllably split power between multiple output ports to generate, literally ‘on-the-fly’, multi-port interferometric optical devices with arbitrary transfer functions. This month, we’ll look at another feature—how an LCoS-based optical processor can, by appropriate optical design, independently manipulate the two polarizations in a signal.

Such a device can be used to generate controllable, wavelength-dependent levels of Polarization Dependent Loss (PDL) and Differential Group Delay (DGD) by using two separate images on the LCoS – one for the “vertical” polarization and one for the “horizontal”.

We are now extending this capability in the latest member of the WaveShaper family, the WaveShaper 2000S Polarisation Processor (press release). This can operate in one of two modes:
• If the LCoS images for the “vertical” and “horizontal” polarization states are chosen to give identical response for both polarizations, then the device operates in a polarization-independent mode, similar to a standard WaveShaper but with two output ports to which the light can be directed.
• Alternatively, by choosing the appropriate images for the “vertical” and “horizontal” sections of the LCoS, and aligning the principal axes of the incoming signal with those of the WaveShaper 2000, it can operate on each of the polarization states independently.

The second, polarization-dependent mode, generates a number of new functionalities of use to the optical communications researcher or engineer. Of particular interest is the ability to generate programmable, wavelength-dependent PDL or DGD for component and system testing.

Here, light from both polarizations is sent to a single port, and the attenuation (or phase, for DGD) for each polarization is varied independently of the other as a function of wavelength. This now provides a unique capability to generate spectrally-varying PDL or DGD. The figures below show how the WaveShaper 2000S can generate both inter-channel PDL (left) across the whole C-band and intra-channel wavelength-dependent PDL (right) – in this case a 20GHz ripple over a 200 GHz superchannel. Note that the algorithms used by the WaveShaper 2000S allow this programmable PDL to be generated with virtually no change in the total transmitted power.

We will be displaying the WaveShaper 2000S Programmable Polarization Processor at the Finisar Booth at ECOC in Amsterdam, September 17-19 (Booth# 500, right inside the main entrance). Come along and see the WaveShaper 2000S in action and tell us what other functionality you would like to see in the increasingly-broad range of Finisar’s Optical Processors.

“PDL and PMD Emulation with Control of Amplitude and Spectral Dependence to a Sub-Channel Level across the C-Band”, Ian G. Clarke et al, Proc OFC 2011, Paper OTuM5

New Applications for LCoS Technology Part II

This week’s blog post is provided by featured author, Dr. Simon Poole.

Following on from last months’ blog on alternative uses for LCoS (Liquid Crystal on Silicon) technology, I’d like to return this month to some of the advanced research that’s being done using the LCoS that’s in our WSS and WaveShaper products.

One of the advantages of LCoS over most other approaches to optical switching is the ability to not only switch incoming light between different output ports but also, if properly programmed, to split the incoming light between multiple output ports. We have, for many years, supported a basic power sharing capability(1) in our DWP 100 range of Wavelength Selective Switches, in which optical power can be shared between an express port and an arbitrary drop port for use in drop-and-continue network architectures. This architectural approach can have advantages from both a traffic management perspective and also from an energy-efficiency perspective (2).

The implementation of optical power sharing in a WSS is, by necessity, limited to a very small subset of what is technically possible due to the need for robustness and simplicity of operation. However, this limitation does not apply when considering other potential uses of optical power splitting in R&D applications. Furthermore, it should be possible to implement wavelength-dependent splitting functions while retaining the phase and attenuation control which is present in our WaveShaper range of Programmable Optical Processors. We have therefore been working with the research team at CUDOS, Sydney University to investigate how such functionality might be implemented and some of the potential applications of the technique (3,4).

In general, splitting to different output ports is possible by a generating a superposition of phase patterns on the LCoS. As the splitting can be performed for individual pixel columns of the LCoS-array, it is possible to vary the splitting and phase as a function of wavelength, which enables reconfigurable implementation of complex interferometric structures.

The researchers have demonstrated the capabilities of the technique by creating various complex structures, including a Mach-Zehnder Interferometer (MZI), two interleaved MZIs for the demodulation of differential phase-shift keying (DPSK) and differential quadrature phase-shift keying (DQPSK) signals, as well as an all-optical implementation of a discrete Fourier Transform (DFT) Filter for demultiplexing optical orthogonal frequency-division multiplexing (OFDM) signals. The results of these are shown in the Figure below.

Figure 1: (a) Insertion loss and phase response of the constructive port of a DPSK Demodulator with an FSR of 43 GHz and an 80 GHz bandwidth; (b) Insertion loss and phase response of the four output ports of a DQPSK demodulator with 40 GHz FSR and 100 GHz bandwidth; (c) Insertion loss and phase response of the three drop ports and one continue port of an all-optical DFT filter with 15GHz channel spacing. In these results, only the phase response of one of the filter channels is shown for clarity.

The results obtained show good agreement with the expected transfer functions of the different devices. In particular, the extinction ratio of the DPSK demodulator is excellent at above 20 dB and the DFT filter shows a sinc response with the maximum in one channel aligning with the nulls of all other channels as expected.

For me, what is particularly exciting about this work is that we have now demonstrated the ability to generate, literally ‘on-the-fly’, multi-port interferometric optical devices with arbitrary transfer functions. This capability should prove a boon to researchers everywhere who need to rapidly prototype demodulators, demultiplexers and other arbitrary interferometric filters.

We will be demonstrating the ability of the WaveShaper to generate these interferometric devices at the ECOC 2012 exhibition in Amsterdam, September 17-19. Feel free to drop by the Finisar booth #500 (you can’t miss it right at the exhibition entrance) any time to see what’s possible!

REFERENCES

1 “High performance ‘Drop and Continue’ functionality in a Wavelength Selective Switch”, S Frisken et al, Proc OFC 2006, Paper PDP
2 “Energy-efficiency of Drop-and-Continue Traffic Grooming”, F. Farahmand et al , Proc OFC 2011, Paper OTuR6
3 “LCOS-based WaveShaper technology for optical signal processing and performance monitoring”, J Schroeder et al, Proc OECC, July 2012
4 “Multi-output-port spectral pulse-shaping for simulating complex interferometric structures”, J Schroeder et al, Proc CLEO, June 2012