Low-operating-energy directly modulated lasers for short-distance optical interconnects

Shinji Matsuo; Takaaki Kakitsuka

doi:10.1364/AOP.10.000567

Advances in Optics and Photonics
Vol. 10,
Issue 3,
pp. 567-643
(2018)
•https://doi.org/10.1364/AOP.10.000567

Low-operating-energy directly modulated lasers for short-distance optical interconnects

Shinji Matsuo and Takaaki Kakitsuka

Not Accessible

Your library or personal account may give you access

Get PDF
Email
Share
Get Citation
Copy Citation Text
Shinji Matsuo and Takaaki Kakitsuka, "Low-operating-energy directly modulated lasers for short-distance optical interconnects," Adv. Opt. Photon. 10, 567-643 (2018)

Export Citation
- BibTex
- Endnote (RIS)
- HTML
- Plain Text
Citation alert
Save article

Check for updates

Related Topics
Table of Contents Category
- Integrated Photonics
Optics & Photonics Topics
?

The topics in this list come from the Optics and Photonics Topics applied to this article.

About this Article
History
- Original Manuscript: March 7, 2018
- Revised Manuscript: June 15, 2018
- Manuscript Accepted: June 25, 2018
- Published: August 14, 2018

Abstract

We review recent developments in directly modulated lasers (DMLs) with low operating energy for datacom and computercom applications. Key issues are their operating energy and the cost for employing them in these applications. To decrease the operating energy, it is important to reduce the active volume of the laser while maintaining the cavity $Q$ -factor or photon lifetime in the cavity. Therefore, how to achieve high-reflectivity mirrors has been the main challenge in reducing the operating energy. In terms of the required output power from the lasers, the required input power into the photodetector and the transmission distance determine the lower limit of laser active volume. Therefore, the operating energy and output power are in a trade-off relationship. In designing the lasers, the cavity volume, quantum well number, and optical confinement factor are critical parameters. For reducing the cost, it is important to fabricate a large-scale photonic integrated circuit (PIC) comprising DMLs, an optical multiplexer, and monitor photodetectors because the lower assembly cost reduces the overall cost. In this context, silicon (Si) photonics technology plays a key role in fabricating large-scale PICs with low cost, and heterogeneous integration of DMLs and Si photonics devices has attracted much attention. We will describe fabrication technologies for heterogeneous integration and experimental results for DMLs on a Si substrate.

Full Article | PDF Article

More Like This

Recent advances in high-contrast metastructures, metasurfaces, and photonic crystals

Pengfei Qiao, Weijian Yang, and Connie J. Chang-Hasnain
Adv. Opt. Photon. 10(1) 180-245 (2018)

AlGaN photonics: recent advances in materials and ultraviolet devices

Dabing Li, Ke Jiang, Xiaojuan Sun, and Chunlei Guo
Adv. Opt. Photon. 10(1) 43-110 (2018)

Subwavelength semiconductor lasers for dense chip-scale integration

Qing Gu, Joseph S. T. Smalley, Maziar P. Nezhad, Aleksandar Simic, Jin Hyoung Lee, Michael Katz, Olesya Bondarenko, Boris Slutsky, Amit Mizrahi, Vitaliy Lomakin, and Yeshaiahu Fainman
Adv. Opt. Photon. 6(1) 1-56 (2014)

Previous Article Next Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (69)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (5)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (38)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Symbol	Parameter	Values	Unit
$A$	Non-radiative recombination coefficient	$5.0 \times 10^{8}$	$s^{- 1}$
$B$	Radiative recombination coefficient	$1.7 \times 10^{- 10}$	${cm}^{3} s^{- 1}$
$C$	Auger coefficient	$1.0 \times 10^{- 28}$	${cm}^{6} s^{- 1}$
$d$	Well thickness	6	nm
$α_{0}$	Internal loss	20	${cm}^{- 1}$
$α_{well}$	Internal loss per single well	2	${cm}^{- 1}$
$η_{i 0}$	Internal efficiency at room temperature	0.4	—
$T_{e 0}$	Characteristic temperature of internal efficiency	60	K
$n_{g}$	Group index	3.8	—
$λ$	Operating wavelength	1.55	μm
$T$	Temperature	300	K
$g_{0}$	Empirical gain coefficient	1742	${cm}^{- 1}$
$N_{s 0}$	Gain coefficient fitting parameter	$- 1.05 \times 10^{18}$	${cm}^{- 3}$
$N_{tr}$	Transparent carrier density	$1.405 \times 10^{18}$	${cm}^{- 3}$
$ϵ$	Nonlinear gain coefficient	$3.0 \times 10^{- 23}$	$m^{3}$
$V_{b 0}$	Built-in bias voltage	0.6	V

Group	Modulation Speed (Gbit/s)	Bias Current (mA)	Slope of $f_{r}$ ( $GHz / {mA}^{0.5}$ )	Temperature (°C)	Cavity Length (μm)	Structure	Year	Ref.
Hitachi	12.5	92	2.4	25	200	Ridge WG	2003	[21]
Hitachi	12.5	92	1.5	115	200	Ridge WG	2003	[21]
Hitachi	40	69	2.8	60	100	Ridge WG	2007	[100]
Fujitsu	25	62	2.5	70	150	SI-BH (DR-laser)	2008	[101]
NTT	25	56	3.3	RT	200	Ridge WG	2009	[102]
NTT	50	60	3.87	RT	150	Ridge WG + BCB	2013	[22]
Hitachi	56	65	3.5	50	120	RS-BH + BCB	2015	[23]
Fujitsu	43	51.2	3.6	50	125	SI-BH (DR-laser)	2015	[103]

Group	Wavelength (nm)	Modulation Speed (Gbit/s)	Bias Current (mA)	Energy Cost (fJ/bit)	Slope of $f_{r}$ ( $GHz / {mA}^{0.5}$ )	Temperature (°C)	Oxide Aperture (μm)	Year	Ref.
TU Berlin	850	25	1.1	77		25	3.5	2012	[24]
TU Berlin	980	42@25°C 38@85°C	3.78 3.6	197@25°C 177@85°C		85	5.5	2014	[108]
IBM-Furukawa	1060	28	2.21	120	9.9@RT 8.6@70°C	70	3.1	2015	[25]
Chalmers	850	40 50	1.7 2.5	99.9 128	17.5		3.5	2015	[109]
Chalmers	850				15@25°C 13.4@85°C	85	3.5	2016	[26]
Chalmers-HPE	1060	50	2.5	100	17.6@25°C 13.7@85°C	25	4.0	2017	[110]

Group	Wavelength (nm)	Modulation Speed (Gbit/s)	Bias Current (mA)	Energy Cost (fJ/bit)	Slope of $f_{r}$ ( $GHz / {mA}^{05}$ )	Temperature (°C)	Cavity Size	Year	Ref.
TUM	1270	25	4.2	240			3 μmϕ	2012	[27]
UC Berkeley	1550	10			3.7	RT	$40 μm \times 40 μm$	2013	[111]
TUM	1530	50	6.8	130	10.1	20	4 μmϕ	2017	[28]
TUM	1530				7.9	RT	5 μmϕ	2017	[112]

Group	Modulation, Speed (Gbit/s)	Bias Current (mA)	Energy Cost (pJ/bit)	Slope of $f_{r}$ ( $GHz / {mA}^{0.5}$ )	Cavity Length (μm)	Year	Ref.
UCSB	4	135	108		440	2007	[160]
UCSB	12.5	62	11	1.185(200 μm) 1.452(100 μm)	200	2014	[161]
Ghent, imec, III-V Lab	28	100	7.15	1.27	340	2015	[162]
DTU, III-V lab	25	138				2017	[163]

Abstract

Cited By

Figures (69)

Tables (5)

Equations (38)

Advances in Optics and Photonics