23 + Mcqs in Single Frequency Injection Lasers Page 1 McqOptions

1.	_________________ is a technique used to render the non-conducting material around the active cavity by producing permanent defects in the implanted area.
A.	Dispersion
B.	Ion de-plantation
C.	Ion implantation
D.	Attenuation
Answer» D. Attenuation

Discussion

2.	The narrow line-width obtained under the CW operation for quarter wavelength shifted DFB laser is ________________
A.	2 MHz
B.	10 MHz
C.	3 MHz
D.	1 MHz
Answer» D. 1 MHz

Discussion

3.	The InGaAsP/InP double channel planar DFB-BH laser with a quarter wavelength shifted first order grating provides a single frequency operation and incorporates a phase shift of ______________
A.	π/2 Radians
B.	2π Radians
C.	π Radians
D.	3π/2 radians
Answer» B. 2π Radians

Discussion

4.	Fabry-Perot devices with BH geometries high modulation speeds than DFB-BH lasers.
A.	True
B.	False
Answer» C.

Discussion

5.	DBF-BH lasers exhibit low threshold currents in the range of ________________
A.	40 to 50 mA
B.	21 to 30 mA
C.	2 to 5 mA
D.	10 to 20 mA
Answer» E.

Discussion

6.	The semiconductor lasers employing the distributed feedback mechanism are classified in _________________ categories.
A.	One
B.	Two
C.	Three
D.	Four
Answer» C. Three

Discussion

7.	The first order grating (l=1) provide the strongest coupling within the device.
A.	True
B.	False
Answer» B. False

Discussion

8.	In the given equation, corrugation period is given by lλb/2Ne. If λb is the Bragg wavelength, then what does ‘l’ stand for?
A.	Length of cavity
B.	Limitation index
C.	Integer order of grating
D.	Refractive index
Answer» D. Refractive index

Discussion

9.	Conventional cleaved mirror structures are difficult to fabricate with the cavity lengths below __________
A.	200 μm and greater than 150 μm
B.	100 μm and greater than 50 μm
C.	50 μm
D.	150 μm
Answer» D. 150 μm

Discussion

10.	DBF-BH_LASERS_EXHIBIT_LOW_THRESHOLD_CURRENTS_IN_THE_RANGE_OF_________________?$
A.	40 to 50 mA
B.	21 to 30 mA
C.	2 to 5 mA
D.	10 to 20 mA
Answer» E.

Discussion

11.	The InGaAsP/InP double channel planar DFB-BH laser with a quarter wavelength shifted first order grating provides a single frequency operation and incorporates a phase shift of ______________$
A.	‚âà√¨‚àö√ë/2 Radians
B.	2‚âà√¨‚àö√ë Radians
C.	‚âà√¨‚àö√ë Radians
D.	3‚âà√¨‚àö√ë/2 radians
Answer» B. 2‚âà√¨‚àö√ë Radians

Discussion

12.	Fabry-Perot_devices_with_BH_geometries_high_modulation_speeds_than_DFB-BH_lasers._State_whether_the_given_statement_is_true_or_false$
A.	True
B.	False
Answer» C.

Discussion

13.	_________________ is a technique used to render the non-conducting material around the active cavity by producing permanent defects in the implanted area
A.	Dispersion
B.	Ion de-plantation
C.	Ion implantation
D.	Attenuation
Answer» D. Attenuation

Discussion

14.	Line-width narrowing is achieved in DFB lasers by a strategy referred as _______________
A.	Noise partition
B.	Grating
C.	Tuning
D.	Bragg wavelength detuning
Answer» E.

Discussion

15.	The_narrow_line-width_obtained_under_the_CW_operation_for_quarter_wavelength_shifted_DFB_laser_is_________________
A.	2 MHz
B.	10 MHz
C.	3 MHz
D.	1 MHz
Answer» D. 1 MHz

Discussion

16.	The semiconductor lasers employing the distributed feedback mechanism are classified in _________________ categorie?
A.	One
B.	Two
C.	Three
D.	Four
Answer» C. Three

Discussion

17.	The first order grating (l=1) provide the strongest coupling within the device. State whether the given statement is true or false.
A.	True
B.	False
Answer» B. False

Discussion

18.	In the given equation, corrugation period is given by l‚âà√≠¬¨‚Ñ¢b/2Ne. If ‚âà√≠¬¨‚Ñ¢b is the Bragg wavelength, then what does ‚Äö√Ñ√∂‚àö√ë‚àö‚â§l‚Äö√Ñ√∂‚àö√ë‚àö¬• stand for?$
A.	Length of cavity
B.	Limitation index
C.	Integer order of grating
D.	Refractive index
Answer» D. Refractive index

Discussion

19.	Conventional cleaved mirror structures are difficult to fabricate with the cavity lengths below
A.	200‚âà√≠¬¨‚à´mand greater than 150 ‚âà√≠¬¨‚à´m
B.	100 ‚âà√≠¬¨‚à´m and greater than 50 ‚âà√≠¬¨‚à´m
C.	50 ‚âà√≠¬¨‚à´m
D.	150 ‚âà√≠¬¨‚à´m
Answer» D. 150 ‚âà√≠¬¨‚à´m

Discussion

20.	A method for increasing the longitudinal mode discrimination of an injection laser which is commonly used?
A.	Decreasing refractive index
B.	Increasing the refractive index
C.	Increasing cavity length
D.	Shortening of cavity length
Answer» E.

Discussion

21.	Which of the following does not provide single frequency operation?
A.	Short cavity resonator
B.	DSM lasers
C.	Coupled cavity resonator
D.	Fabry-Perot resonator
Answer» E.

Discussion

22.	Device which apply the frequency-selective feedback technique to provide single longitudinal operation are referred to as ________________
A.	DSM lasers
B.	Nd: YAG lasers
C.	Glass fiber lasers
D.	QD lasers
Answer» B. Nd: YAG lasers

Discussion

23.	__________________ may be improved through the use of frequency-selective feedback so that the cavity loss is different for various longitudinal modes.
A.	Frequency selectivity
B.	Longitudinal mode selectivity
C.	Electrical feedback
D.	Dissipated power
Answer» C. Electrical feedback

Discussion

Explore topic-wise MCQs in Optical Communication.

_________________ is a technique used to render the non-conducting material around the active cavity by producing permanent defects in the implanted area.

The narrow line-width obtained under the CW operation for quarter wavelength shifted DFB laser is ________________

The InGaAsP/InP double channel planar DFB-BH laser with a quarter wavelength shifted first order grating provides a single frequency operation and incorporates a phase shift of ______________

Fabry-Perot devices with BH geometries high modulation speeds than DFB-BH lasers.

DBF-BH lasers exhibit low threshold currents in the range of ________________

The semiconductor lasers employing the distributed feedback mechanism are classified in _________________ categories.

The first order grating (l=1) provide the strongest coupling within the device.

In the given equation, corrugation period is given by lλb/2Ne. If λb is the Bragg wavelength, then what does ‘l’ stand for?

Conventional cleaved mirror structures are difficult to fabricate with the cavity lengths below __________

DBF-BH_LASERS_EXHIBIT_LOW_THRESHOLD_CURRENTS_IN_THE_RANGE_OF_________________?$

The InGaAsP/InP double channel planar DFB-BH laser with a quarter wavelength shifted first order grating provides a single frequency operation and incorporates a phase shift of ______________$

Fabry-Perot_devices_with_BH_geometries_high_modulation_speeds_than_DFB-BH_lasers._State_whether_the_given_statement_is_true_or_false$

_________________ is a technique used to render the non-conducting material around the active cavity by producing permanent defects in the implanted area

Line-width narrowing is achieved in DFB lasers by a strategy referred as _______________

The_narrow_line-width_obtained_under_the_CW_operation_for_quarter_wavelength_shifted_DFB_laser_is_________________

The semiconductor lasers employing the distributed feedback mechanism are classified in _________________ categorie?

The first order grating (l=1) provide the strongest coupling within the device. State whether the given statement is true or false.

In the given equation, corrugation period is given by l‚âà√≠¬¨‚Ñ¢b/2Ne. If ‚âà√≠¬¨‚Ñ¢b is the Bragg wavelength, then what does ‚Äö√Ñ√∂‚àö√ë‚àö‚â§l‚Äö√Ñ√∂‚àö√ë‚àö¬• stand for?$

Conventional cleaved mirror structures are difficult to fabricate with the cavity lengths below

A method for increasing the longitudinal mode discrimination of an injection laser which is commonly used?

Which of the following does not provide single frequency operation?

Device which apply the frequency-selective feedback technique to provide single longitudinal operation are referred to as ________________

__________________ may be improved through the use of frequency-selective feedback so that the cavity loss is different for various longitudinal modes.