As the negotiations continue at both Rio+20 and the G-20 Summit I'm seeing reports of both hope and fear. The hope seems to be coming from the non-government and business sectors and the fear from the government diplomats and delegates. At Rio there is little progress other than watering down the provisions of the outcomes document so that there will be greater agreement. I've been following the international press's take on Rio and last night I noticed that there was typically a new story being posted from around the world every 15 minutes. Unfortunately many of the stories confirm my fears that the Rio+20 is turning into a backtracking on key issues that were addressed 20 years ago and the US is leading the backtracking. Nonetheless there is hope that the various discussions here will lead to commitments to do more to advance sustainable development.

Yesterday was the higher education sustainability associations' side event. Below is Kim Smith's report from the presentation:

"Do you remember the lovely young girl who blew all of the delegates away in 1992? http://www.youtube.com/watch?v=uZsDliXzyAY Well, Severn Suzuki is all grown up and is still doing amazing work. I didn't actually realize it was her when she was speaking on a panel about climate change today until everyone started taking pictures of her at the end. She is still as articulate, as ever, but poignantly stated that she is ashamed of her country, Canada. At least I got a chance to give her my card with AASHE's website on it and a flyer for our presentation.

She didn't come to our higher education presentation but plenty of others did. Over 60 people came to our session, even though it was from 7:30 to 9:00. http://www.uncsd2012.org/index.phppage=view&nr=1224&type=230&menu=38 We were able to share many examples of all of the good work being done by colleges all over the world. Alas, some rather dry presentations put a damper on the enthusiasm in the room, but the Higher Education Treaty appeared to be received well and many people asked some deep questions about the role of the UN, how to change values, how to address equity issues, government support, and the role of developing countries.

A rather maddening experience for all involved was the last-minute shuffling of the Side Event locations. Given the unresolved negotiations, the delegates basically commandeered the pavilion in which we were supposed to present and the poor Summit organizers had to rearrange all of the rooms. This required some scrambling on our part and has created a lot of frustrated people, but, again, 60 people found us and shared in our commitment to supporting higher education in sustainable development.

We'll see what tomorrow brings. I am particularly looking forward to attending the launch of the Higher Education Sustainability Initiative and then going to Vandana Shiva's talk called "Women Leading the Way: Mobiliizing for an Equitable, Resilient and Thriving Future" http://www.uncsd2012.org/index.php?page=view&type=1000&nr=614&menu=126

We will continue to cross our fingers that some big decisions will be made in Rio to create a clear global vision for a sustainable future."

A handout was provided to delegates attending the side event and will continue to be distributed throughout the conference.

Luke 9:21-26 (NIV)

21Jesus strictly warned them not to tell this to anyone. 22And he said, “The Son of Man must suffer many things and be rejected by the elders, the chief priests and the teachers of the law, and he must be killed and on the third day be raised to life.”

23Then he said to them all: “Whoever wants to be my disciple must deny themselves and take up their cross daily and follow me. 24For whoever wants to save their life will lose it, but whoever loses their life for me will save it. 25What good is it for someone to gain the whole world, and yet lose or forfeit their very self? 26Whoever is ashamed of me and my words, the Son of Man will be ashamed of them when he comes in his glory and in the glory of the Father and of the holy angels.

Reflection:

The disciples were probably still trying to process what Jesus was saying must take place when Jesus goes on to explain what this means for their lives. This is a critical time for His disciples. What is unthinkable to them is about to happen. But Jesus’ heart for them is to not only know what will happen to Him on the cross, but also to fully embrace what it means to be His disciple. He wants them to know that the way of the cross is suffering. This is what we are to hear as well. The encouragement is that if the cross we are called to bear is of Him, God will work it for His glory.

Responding to the Transmission:

This is probably not what we would think of when asked about our favorite verse in the Bible. But this is too important and central to the message of the cross to ignore. Jesus says to anyone who wants to be His disciple to deny themselves, take up their cross daily and follow. Today, let the Spirit of God testify to the truth of this passage as we read and reflect. As we come let’s not try to look for another way, but allow the Spirit’s work in us so that we come with greater faith, greater love, and greater hope as we hear Jesus’ call to us: “then take up your cross and follow Me”.

Seth Sawyers ’99, history, published an op-ed about childhood memories of his dad in the Father’s Day issue of the Baltimore Sun. Sawyers, who recently finished a memoir about growing up in the Maryland Appalachians in the 1980s, also teaches writing classes at UMBC.

An excerpt from the piece:

The zombie trend continues to spread across the pop cultural landscape and shows little sign of slowing down. Speaking with The Baltimore Sun‘s John-John Williams IV for a June 9 story entitled “Pop culture’s undying affection for zombies“, Arnold Blumberg ’93, English, an adjunt faculty member in UMBC’s English department and co-author of Zombiemania: 80 Movies to Die For, illustrated the history of this now-ubiquitous staple of modern popular culture, as well as theorizing as to why the walking undead seem to have captured our culture’s imagination in recent times.

“There has never been a figure that has reflected all the fears we have as the zombie,” he told Williams. “It is the closest type of monster to us. They are us and we are them. The zombie comes down to some form of being a human being.”

Originally posted in UMBC Insights.

Read more about Blumberg in UMBC Magazine.

Ph.D. Dissertation Defense

Fabrication and Operation of Integrated Distributed-Bragg-Reflector
Thermally Tunable Quantum Cascade Lasers

Liwei Cheng

10:00am Friday, 22 June 2012
Center for Advanced Studied in Photonics Research Conference Room

Quantum cascade lasers (QCLs) that emit in the mid-infrared (IR) range between 3 and 10 μm of the electromagnetic spectrum play an important role in optical gas sensing and molecular spectroscopic applications because several important environmental molecules such as CO, CO2, CH4, and NH3 are known to exhibit strong absorption lines in this mid-IR range. To differentiate such fine absorption features as narrow as a few angstroms, a single-mode QCL with an extremely narrow spectral linewidth, broadly tunable over the molecular absorption fingerprints and operating at sufficient optical power at room temperature, is highly desirable. We present, in this dissertation, two major studies on mid-IR QCLs, one being an improvement in device performance through a buried-heterostructure (BH) regrowth study, and the other being a realization of single-mode tunable QCLs integrated with distributed-Bragg-reflector (DBR) grating and thermal tuning mechanism.

Efficient heat dissipation in the QCL active region, which is crucial for high optical-power operation, can be effectively achieved using BH waveguides laterally embedded with InP grown by metal-organic chemical vapor disposition. We have experimentally studied the effects of the structural features of mesas, such as mesa orientation, geometry, sidewall-etched profile, and the length of the oxide overhang, on the BH regrowth. We find that the mesa oriented in the [01 1 ] direction with smoothly etched sidewalls produces a satisfactory planar growth profile and uniform lateral growth coverage and that a mesa-height–to–overhang-length ratio between 2.5 and 3.0 is effective in reducing anomalous growth in the vicinity of oxide edges. As a result, high-power QCLs capable of producing multi-hundred milliwatts at room temperature at ~4.6 μm and ~7.9 μm through reproducible BH regrowth results have been demonstrated.

We have also demonstrated single-mode tunable QCLs operating at ~7.9 μm with an internal DBR grating structure and thermal tuning scheme incorporated. A special flip-chip bonding configuration and device assembly utilizing two copper heatsinks—one for the gain section and the other for the DBR grating section—were devised and constructed to achieve separate temperature controls in both sections. A miniature thermoelectric (TE) cooler dedicated to the DBR grating section was implemented to control the DBR grating temperature while the gain section was kept at a different temperature to achieve single-wavelength tuning. Under ±1000 mA bias conditions, a quasi-single-wavelength tuning range of ~7.2 cm-1 was realized across the TE cooler temperature span, combined with an additional temperature contrast of 56 °C between the two heatsinks (gain/DBR = 10/66 °C) owing to the implementation of additional temperature-controlling elements. We have also developed a two-dimensional thermal model to investigate the thermal dynamics in the device, including the temperature distribution and thermal dependency of each section, and the thermal response time, which ultimately dictates the wavelength tuning speed. We find that a 250-μm passive section located between the gain and DBR grating section can significantly improve temperature uniformity in both the sections as it absorbs most temperature gradients. Further, a swift thermal response time of ~7 ms is simulated if the DBR grating section is directly bonded on the miniature TE cooler.

More importantly, we have realized a monolithic photonic integration platform, both thermally and electrically, for mid-IR QCLs. The QCLs fabricated in this dissertation possess two major functionalities. The gain section, an active component, is electrically pumped to provide optical gain and is kept at a temperature different from the DBR grating section, and the DBR grating section, a passive component, provides optical feedback for single-wavelength emission and subsequently tunes the emission wavelength through a local temperature variation. Such thermal and optoelectronic integration opens new perspectives for mid-IR QC technology.

Committee: Drs. Fow-Sen Choa, Anthony Johnson, Li Yan, Ryan Robucci, Terrance Worchesky and Jocob Khurgin